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Guidelines for minimum impact trail location in Colorado conifer forests

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Title:
Guidelines for minimum impact trail location in Colorado conifer forests
Creator:
McCandless, Mary Lou
Language:
English
Physical Description:
57, [21] leaves : charts (some folded), folded maps ; 28 cm +

Subjects

Subjects / Keywords:
Trails -- Environmental aspects -- Colorado ( lcsh )
Trails -- Planning -- Colorado ( lcsh )
Trails -- Environmental aspects ( fast )
Trails -- Planning ( fast )
Colorado ( fast )
Genre:
Academic theses. ( lcgft )
bibliography ( marcgt )
theses ( marcgt )
non-fiction ( marcgt )
Academic theses ( lcgft )

Notes

Bibliography:
Includes bibliographical references (leaves 73-78).
General Note:
Submitted in partial fulfillment of the requirements for the degree, Master of Landscape Architecture, College of Design and Planning.
Statement of Responsibility:
by Mary Lou McCandless.

Record Information

Source Institution:
University of Colorado Denver
Holding Location:
Auraria Library
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
15525264 ( OCLC )
ocm15525264
Classification:
LD1190.A77 1986 .M24 ( lcc )

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Full Text
V
GUIDELINES FOR
MINIMUM IMPACT
trail location
In Colorado
Conifer Forests
Prepared
in Partial Fullment for Maste] University of Coloi College of Design
Landscape Architecture
at Denver
Planning
Degree
** mry teu McCandless
r........;
Date Due
989
THIS BOOK CONTAINS 20 SLIDES IN POCKET OF INSIDE BACK COVER.


Thesis Caimittee Signatures
JuuL Z6//9&


TABLE OF CONTENTS
PART Is THESIS RESEARCH
SECTION I - The Scope of This Thesis ..................................... 1
SECTION II - Wilderness Trail Conditions Today ............................ 4
SECTION III - Suirmary of Data ..............................................6
SECTION IV - Guidelines for Locating Minimal Impact Trails ................10
SECTION V - Overview of Relevant landscape Characteristics .............. 21
SECTION VI - Finding Overall Trampling Resistance and Trail Location
Suitability - The Author's Research Process ................ 29
PART II: CASE STUDY.......................................................... 48
APPENDIX I - Wilderness Act of 1964 ................................... 58
APPENDIX II - Wilderness Use............................................. 63
APPENDIX III - Colorado Conifer Forest Plant Associations:
Resistance to Trampling.................................... 64
APPENDIX IV - Scale of Trail Location Suitability....................... 68
BIBLIOGRAPHY................................................................ 73


SECTION I - the Scope of This Thesis
Our wilderness areas are being loved to death. Trail and campsite conditions have been declining in recent years due to increased use. Research shews, however, that frequency of use is not the sole factor in trail and campsite degradation. (8, 9) Perhaps more important are landscape characteristics and user practices. (8, 9) Most trails in wilderness today are remnants of old fire-fighting or stock-driving trails. (13, 41) They tend to follow streams uphill and end, perhaps at a lake. Or they cross over a saddle and dewn another draw. These streamside locations are often soggy, and hard to maintain. (13)
The assumption of this thesis is that seme trails in wilderness areas are not located in areas most resistant to trampling. The thesis hypothesis is that relative resistance to trampling impacts can be determined, and that trail location guidelines can be drawn on the basis of that resistance. The guidelines which result will then be tested in a case study. For the purpose of this thesis only, the location of the Contenental Divide National Scenic Trail will be determined as it runs through Huston Park Wilderness Area, Medicine Bow National Forest, Wyoming.
Trail location guidelines generated by this thesis will be usable by anyone designing a trail in Colorado coniferous forests. The guidelines are intended to be used in conjunction with mapped plant associations and soils for each specific project. However, the basic principle of trampling resistance as determined by this thesis, should still enable satisfactory trail location without extensive resource mapping. The scope of this thesis has been to determine which physical properties of soils and vegetation contribute to
1


resistance to trampling; and in turn, to identify how those properties manifest into a physical form which can be readily mapped and identified in the field.
The physical properties of soils, in part, determine erosion of the trail surface. Physical properties of vegetation determine denudation of the trail margins.
Although in the guidelines sane consideration has been given to hiker experience, this thesis is primarily concerned with land resources and their resistance to trampling as a basis for locating trails. The element of user preference to trail location was omitted frcm the evaluation process due to limitation on time and project scope. Knowledge of user preference is certainly of equal importance as land resistance in determining trail location, and together user and land factors would determine the final most workable locations. Research on user preference to trail location is clearly needed.
The value of this thesis' results range beyond trail location. The principles of land resistance to trampling can be applied to other forms of outdoor recreation and to other uses on native soil and vegetation conditions. In addition, the model for trampling resistance is a tool which could be applied to other areas of the country by inserting local native vegetation into the model for plant associations.
Trail location guidelines for minimal trampling impact are clearly needed. No such guidelines exist to the author's knowledge. No other guidelines address the importance of vegetation as it relates to trail margins. Other guidelines address trail grade, but frcm a user's standpoint rather than that of soil erosion. (35, 36, 37)
2


One of the major builder of trails in the west is the U.S. Forest Service. That process of trail location begins with the agency's planning process, condsidering objectives set for each Forest in that Forest's Land Management Plan. (40) The process then considers the predetermined level of trail development and use, according to the Recreation Opportunity Spectrum System. (39) Many forest management and administrative factors are addressed before the trail corridor is located. (36, 40, 39) The general trail corridor is located by looking at aerial photos and topographic maps, then the trail centerline is staked in the field. (35) Standards for trail grade and length are set, but relate to trail difficulty and not to resource protection. (35) No mention is made to minimize soil erosion, or encourage use in more resistant vegetation types.
As increased recreational use intensifies inpacts on wilderness land, the need arises to relocate stretches of problem trails. Due to lack of funding, trails in wilderness receive very little maintenance. Therefore, all trails should be in the most optimum locations - where impact from trampling is minimal. The guidelines produced by this thesis would be particularly useful for relocation of problem wilderness trails. However, these guidelines are useful for location of trails anywhere in a Colorado coniferous forest.
3


SBCTICN II - Wilderness Trail Conditions Today
All designated wilderness areas are a result of the Wilderness Act of 1964. (See Appendix I). It established the National Wilderness Preservation System to include tracts of wild land so that "settlement does not occupy and modify" all lands within the United States. Wilderness is defined in the Act as "land untranmeled by man, man is a visitor who does not remain". It is further defined as undeveloped federal land which 1.) appears primarily natural and unmodified by man, 2.) has outstanding opportunities for solitude or primitive and unconfined type of recreation, 3.) has at least 5,000 acres, and 4.) may also contain ecological, geological, or other features of scientific, educational, scenic, or historical value. Ihe Act mandates that designated wildernesses be preserved in their natural state for use and enjoyment by present and future generations. Thus, wilderness areas must be managed to protect the existing natural resources, yet at the same time allow wilderness-dependent types of recreation.
A parcel of land characterized as primitive can only become designated as a wilderness area by presidential proclamation or an act of Congress. In the lower forty eight states, there are 439 wilderness areas covering 86 million acres, (41) and numerous more proposed areas before Congress awaiting decision. (See Appendix II). The Forest Service, National Park Service, Bureau of Land Management, and Fish and Wildlife Service are the federal agencies managing the existing and proposed wilderness areas.
Ihere is a substantial and increasing body of research concerning recreational use in wilderness - much of it originating at the University of Montana and the
4


Forest Service Range and Experiment Station in that region. That research identifies several major inpacts of recreational use, all related to trampling. (3, 6, 7, 8, 9, 22, 33) The primary inpact to trails is soil erosion, which deepens the trail tread. (3, 5, 6, 7, 33) Sane stretches of trails studied in Montana were three feet (3) Loss of vegetative cover on trail margins widens the trail tread. (3, 5, 6, 7, 33) This loss of cover results in exposure of bare mineral soil, which is then subject to erosion and compaction. (28) Also noted is a change in species composition along trail margins, occurring in roughly three-foot wide bands on either side of the trail. (3, 6, 7) This change in ccmpositon is due to invasion of species into the disturbed margins.
Inpacts to campsites are much the same as to trails. Deterioration of campsites happens very quickly, and revegetation is slew. Extreme loss of vegetative cover - 74% - typically occurs with only light use, one or two nights a year.
(8, 9) After the initial deterioration, increased use is unlikely to cause a great deal more damage. (8, 9) Thus, limiting use is not the total answer to the problem. The conditions of trails and campsites are more a function of user practices and inherent site characteristics. The identification of site characteristics most resistant to inpacts is the direction of this thesis.
5


SECTION III - Summary of the Data
The key to most suitable trail locations lies in determining landscape types which are most resistant to the effects of trampling. This involves analysis of the trail surface itself - of the soils and trail grades, as well as the trail margins - or the surrounding vegetation.
To determine resistance of the trail surface, the effect of different trail grades on soil textures was analyzed. The Universal Soil Loss Equation was used to calculate erosion rates on various trail scenarios. Trail grades selected for use with the equation were: 3%, 6%, 9%, 12%, 15%, 20%, and 30%. Ihe resultant erosion rates were plotted on a graph to identify trends related to trail grades. Three trends emerged: 1) on trails of 6% and less, the texture of soil was not a significant factor in the rate of erosion. Trail grade was the most important factor influencing erosion;- 2) on trail grades between 9% and 15%, soil texture was more important than grade. This is especially true between 12% and 15%. Coarser-textured soils on these grades are significantly less erodable than finer-textured soils. 3) on grades above 15%, all textures are highly erodable.
To determine the resistance of trail margins, the combinations of vegetative form and moisture regime of different plant communities was analyzed.
Vegetative forms and moisture regime determine a plant's overall resistance to being killed by trampling. Vegetative form also determines a plant's ability to spread vegetatively into denuded trail margins. The different vegetative forms of forest understory plants were analyzed for trail margin suitability. They were granminoids, shrubs, and forbs. Gramminoids are grass-like plants. Shrubs
7


are multiple-stemmed plants with sane amount of woody growth. Forbs are all herbacious plants which are not gramminoids, lichens, or mosses. These vegetative forms were analyzed in dry, moist, and wet scenarios. The results of that analysis produced a ranking of vegetative resistance to trampling. It shewed that dry graitminoid cannunities are the most resistant to trampling, followed by dry shrubs, moist grairminoids, and finally moist shrubs. Forb and all wet cannunities have very poor resistance to trampling and are unsuitable for trail margins. This ranking of vegetative resistance become a model of suitability for trail margins. The model can be used to determine suitability of native plant associations for trail margins.
The model is vised by inserting a particular plant association into its appropriate category in the model. For example, the plant association subalpine fir-Englemann spruce/ross sedge grows in very well-drained areas, having a dry moisture regime. Ross sedge, the understory species, is a graitminoid.
Therefore, subalpine fir-Englemann spruce/ross sedge is a dry graitminoid plant association. The model indicates that all dry graitminoid plant associations have a high suitability for trail margins. The model can be used in this manner to identify trail margin suitability of any plant association of any region.
The model is applicable to any region because it is based on universal factors which contribute to trampling resistance.
The different trail grades that were used in calculations of soil erosion where matched to appropriate hi11slope positions where that grade of trail would most likely be found.
8


The different combinations of hillslcpe position and trail grade, with suitable vegetation forms were ranked for overall suitability for trail location. This formed a scale of location suitability. Hie most suitable location for trails is: 0% - 3% trails on sunmits, toeslcpes, and valley bottoms with dry gramminoid plant communities. Hie least suitable trail location is: 6% - 9% trails on backslopes with moist shrub plant ccmnunities. Unsuitable locations for trails are on: steep trail grades, wet plant sites, and forb dominated understory ccmnunities.
Finally, guidelines for minimum inpact trail location were developed. Hie guidelines are a process to aid the trail designer in locating the most suitable trail corridors from within an entire project site. Hiey are a planning tool to be used in the first stage of trail design on the drawing board. Hie guidelines are the result of a long analysis done by the author to help her identify landscape characteristics which contribute to trampling resistance. Hie professional should apply only the guidelines to locate resistant trail corridors. Hie analysis process does not need to duplicated each time the prof essional wishes to locate trail corridors. Final trail centerlines can only be determined in the field, considering all surface conditions.
Hie scope of this trail suitability analysis was limited to the factors of soil resistance to water erosion and vegetative resistance to trampling. Other factors were emitted due to the limitation on time. Factors excluded from consideration were soil resistance to wind erosion, the effects of hiking shoes and horses on soil erosion, and the analysis of user preferences.
9


SECTION IV - Guidelines for Locating Trails of Minimal Trampling Impact
The following guidelines are a process for locating trail corridors based on resistance to trampling. Trail locations resulting frcm these guidelines will result in minimal impact to trampling. These guidelines are intended for use by the landscape architect in the initial phase of a trail design project. The process outlined is a planning tool to aid him in locating the most suitable trail corridors from within the entire project site. The professional must have access to reliable resource maps to be able to use this process. He must have:
1) vegetation mapped shewing dominant species of the forest understory, 2) a soil survey shewing textural classes of the top 4" - 6" of soil, such as an SCS soil survey, 3) a topographic map shewing all surface landmark features such as streams, lakes, falls, mines, glaciers, townsites, trails, and roads.
These maps must all be at the same scale. The larger the scale of the maps, the greater the amount of detail will be shewn. Large scale maps are preferable to small scale maps. However, often the professional will only be able to obtain the necessary information at a scale of 1:24000. Working at that scale it is necessary to understand that the narrowest trail corridor located will be roughly 40-50 feet wide. The planning process outlined in these guidelines will enable the professional to locate the most suitable trail corridors on the project site as a necessary first step in final trail location. It is manditory to realize that final trail centerlines can only be determined on the ground, considering all surface conditions..
10


DESIGN CRITERIA
There are four major factors necessary to consider for locating trails that are resistant to trampling. They are: vegetation types that are resistant to trampling; the combination of soil textures and trail grades that are resistant to water erosion; relative hillslope positions; and destination and access points of the site.
Vegetation
The vegetation that surrounds a trail is important because it can prevent the trail from becoming excessively wide. Trails should be located on vegetation that is resistant to being killed by trampling. This initial resistance helps prevent the trail margins from expanding. Also important is the ability of the surrounding vegetation to spread back into denuded patches of the trail margins. An anlaysis of factors contributing to vegetation suitability for trail margins appears in the data section of this thesis. The results of that analysis produced the following ranking of vegetation types.
High Suitability - 1. dry gramminoid communities
2. dry shrub cannunities
3. moist gramminoid cannunities Fair Suitability - 4. moist shrub communities
Unsuitable - wet or forb communities
/
Trails should not be routed through areas with understories dominated by forbs or boggy areas with wet vegetation. These types of vegetation have poor resistance to trampling.
11


Soils
Hie soils and grades of a trail are important because together they determine hew eroded and deep a trail can get. Trails located on highly erosive, finer-textured soils should have gentle grades to minimize the effects of water erosion. Fine textured soils are constraints to steep trail grades. Coarser textured soils are more resistant to water erosion than fine textured soils, and can tolerate steeper trail grades. These coarser textured soils and stable rock are opportunities for steeper trail grades. Keep trail grades to the following limits.
Soil Texture
fine loams
silts
clays
rocky soil coarse loams
stable rock
Trail Grade 0% - 6%
0% - 15%
0% +
Hillslope Position
Identifying the relative positions, or parts, of a hillslope can help the trail designer in two ways. Firstly, having the positions delineated helps the designer to understand a site's topography and landform at a quick glance. This can help the designer to provide a better variety of trail location to heighten the user's experience. Secondly, the delineation of hillslope positions can give the designer a quick idea of probable trail grades at different places on the hill.
12


The positions on a hillslope are:
surmtit: flattest part of the top of the hill
shoulder: transition between summit and backslope; where the gradient o
the hill starts to increase backslope: steepest part of the hill
footslope: transition between backslope and toeslope; where the gradient of the hill starts to decrease.
toeslope: bottom of the hill; transition between footslope and valley
valley: flattest land between 2 hills.
Trails of certain grades are more likely to occur on particular positions of a hillslope. They are:
summit and shoulder: backslope: footslope, toeslope, valley:
0% - 6% 0% +
0% - 6%
Destination and Access Points
Destination points and access points are the focal points of a trail system. It is important that a trail is located where hikers will use it. Otherwise, the hiker will create his own path to get to his destination, and others will follow his lead. Soon a new path appears. To avoid unplanned trails, an adequate circulation pattern must be provided which encompasses a variety of probable destination points over the entire site. In addiditon, access points to the


internal circulation pattern roust be sufficiently spaced to avoid overuse and underuse of any one area.
Possible Destination Points: lakes, falls, glaciers, mines, ghost towns, existing trails, etc.
Access Points: existing trails, roads, campgrounds picnic areas, etc.
The process of locating minimal impact trails has two parts: the mapping stage and the planning stage.
MAPPING STAGE
1. Map the vegetation types. Group together and map as a single unit all dry graitminoids. Label these as l's. Do the same for dry shrubs, moist grarrtninoids, and moist shrubs. Group together wet and forb plant associations. These will be constraints to trail location. label the units as such:
dry graitminoids - 1
dry shrubs
2
moist graitminoids - 3
moist shrubs
4
wet and forbs
U
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This is a ranking system which indicates trampling resistance at a quick glance. Appendix III can be used to identify which category a plant is in.
2. Map the highly erodable soils. Notice all rock areas, or rocky soil, cobbly, gravelly, or sandy loams. These will provide the most flexibility for trail grades. Map all other soil textures as 1 unit and label it as a highly erodable soil. These soils will be constraints to trail grades.
3. Map the hillslope positions. Indicate as single units:
1) sunmits and shoulders
2) backslopes
3) footslopes, toeslopes, and valleys
The point at which the slope of the hill starts to steepen will be the lower edge of the summit/shoulder unit. Similarly, the point at which the slope of the hill starts to flatten out will be the lower edge of the backslcpe unit.
All gently graded bottomland will be a valley unit.
4. Map the probable destination points and access points.
PLANNING STAGE
5. Create an internal circulation pattern. Route possible trail corridors through suitable plant associations, linking destination points together. Route the corridors through a variety of different plant associations if possible.
15


Avoid using lakes with boggy areas nearby as destination points.
Fran each major access point on the border, route an access trail to the internal circulation system. Route the different access trails to join the internal system at widely separated junctions. Avoid creating circulation patterns which encourage overuse at one destination point and underuse at another.
If there is only one probable destination point in the site, create a loop out of the acoess trail. A loop trail is more interesting than a trail that has to be completely backtracked.
6. Use a variety of trail grades and hillslope positions if possible. Variety can be added to a trail be routing it over different positions of a hill. For example, the trail may follow a valley for a while, then climb over a ridge and down to another valley. Biis must be done artfully to avoid seeming contrived.
7. Check that the trail grades are appropriate with the underlying soil texture. On the finer soils keep trail grades under 6%. Trail grades of 9% -15% should only occur on coarser soils. Trail grades over 15% should only occur on very rocky soil or stable rock. Make any trail grade adjustments as necessary to accomodate soil texture.
16


8. Locate final centerlines in the field, making any necessary adjustments for
site conditions.
Additional considerations to final trail location - based on preference of
resistance in vegetative form, soil texture, and moisture:
1. In a choice between granrninoid or shrub dominated understories, remember that granminoids are more resistant to trampling.
2. Rather than taking a trail through the center of a meadcw, route it along one edge, preferably the north or east edge, as it may be drier there.
Hie trail, or it's users, are less conspicuous there. In addition, the interface of a meadow and forest can be a more exciting position than the middle of a meadow because it relates to both meadcw and forest.
3. Follow a stream or valley along its north or east side, as it may be sunnier and drier there. This is due to the angle of the sun. The south or west side of a valley may remain in shade for most of the day.
4. Use the raised bench along a stream, if there is one, rather than the edge of the stream itself. If the bench is raised high enough above the water table to be dry, it will be drier than the edge of the stream.
5. Cross a stream at its driest plant association. Avoid crossing at a wet association. Wet plant associations are common along streambanks, but are easily damaged.
1?


6. Approach lakes and ponds frctn their driest and highest side. Use plant associations and elevation differences as a guide. Often the dcwnhill edge of a lake will have a boggy area. These boggy areas are fragile and should be avoided.
7. Choose exposed ridgetcps rather than protected ones as vista vantage points. Plant associations will be dry there and vegetation thinner, providing better opportunities for long distance views. Vegetation will be less fragile there, and the trail will be drier.
8. Provide a variety of aspects, plant associations, trail grades, and hillslcpe positions within one day's travel to increase user enjoyment of the trail.
9. Cross a stream or route the trail witin 100 - 200 feet of a stream within a half day's travel to provide access to drinking water if no other source exists. The best and purest stream water for drinking is obtained where the water is moving quickly. The safest place to cross a stream is where it is wide and shallow. Try to find a place to cross which has both good crossing and easily accessable drinking water close by.
10. Provide opportunities for long distance panaramic viewing from high vantage points, for scenic value and hiker orientation. Hiker orientation is especially important as the trail gets farther away from its beginning point.
18


11. Avoid routing trails in proximity to known wildlife nesting, denning, or birthing sites. Human activity can disturb wildlife by interfering with crutial breeding and young-rearing habits. This can become dangerous for the user, and jeopardize the success of sane species' ability to reproduce.
12. Avoid routing trails through dense shrubland and known riparian feeding sites in bear country. Bears are unpredictable and may attack with little or no provocation.
13. Avoid routing trails over very loose rock. Ihis can be extremely dangerous, resulting in personal injuries and rockslides. If a trail must have a grade over 15% - 20%, route it over very stable rock or rocky soil.
14. Do not create any new trails above timberline. The tundra is extremely fragile and takes generations to revegetate. If trail routing cannot avoid close proximity to tundra, route the trail to cane closest to tundra where the tundra carmunities are dry meadow types. Canpletely avoid snowbank and moist meadow tundra communities.
15. Any stretches of trail which are unavoidably likely to cause maintenance problems should be located as close as possible to access points which are accessible by vehicles.
Tradeoffs in the design of a trail:
Any trail system is only as satisfactory as the degree to which it satisfies the
19


loser. It is important that the designer foresee the users' needs and attempt to fulfill then as closely as possible. Care should be taken to provide variety in all aspects of the design. To design a trail which has very little impact on the landscape, yet is uninspiring to the user is a big mistake. The trail may not be used at all. Or, users may create their own trail network to achieve their desired goals. In both cases, an opportunity has been missed. It is far better to design trails which have little impact on the land and also provide an exciting hiking experience. Sometimes it is desireable to foresake minimum impact for a heightened user experience. For example, it may be desireable to provide several stretches of steep trail grades to break up an otherwise boringly level trail. Perhaps it may be desireable to lead a trail through a stretch of lush, shady forest vegetation to break up the monotony of a sunny meadow trail. If the trail does not provide enough variey on its own, users will seek that missing variety off the trail. This defeats the purpose of a trail: to get users where you want them to go and provide them a good time getting there.
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SECTION V - An Overview of Relevant Landscape Characteristics
SOILS
Soils are made up of different sized particles, including sand, silt, and clay. Sand is considered those particles 2mm - .05mm in size, silt is .05mm - ,002mm, and clay is any particle smaller than .002mm. Ihe size of soil particles plays an important role in hew those particles behave. Clay particles are the tiniest mineral flakes of their parent rocks - the end product of extensive weathering. They are highly active chemically and bond easily to other particles, chemicals, and water. Sand grains are those particles most resistive to weathering forces, and thus are quite chemically inactive. Silt are those particles intermediate in size and weathering between clay and sand, and are also chemically inactive. Sand and silt particles in a soil function as skeletal material, whereas clay and other colloids, such as organic matter, provide all chemical activity in that soil.
The relative proportions of different sized particles in a soil determine its textural class. The name of a textural class relates to the predominant size of particles present or manner in which the soil behaves. When sand, silt, and clay and their properties are all represented, the texture is a loam. Figure 1. depicts textural classes by preportion of particle sizes. (27)
Note that a sand can contain up to 10% clay particles, whereas a clay can contain as little as 40% clay particles. Soils with high percentages of sand or gravel are termed coarse soils. Those soils with high percentages of clay are termed fine soils. See the following chart for comparison. (27)
21


Figure 1
. Soil Textural Classes. From The Nature and Property of Soils by Brady.
Figure 3:5. Relationship between the class name of a soil and its particle size distribution. In using the diagram the points corresponding to the percentages of silt and clay present in the soil under consideration are located on the silt and clay lines, respectively Lines are then projected inward, parallel in the first case to the clay side of the triangle and in the second case parallel to the sand side. The name of the compartment in which the two lines intersect is the class name of the soil in question.
Cannon Name Sandy soils
Loams
Texture
Coarse
Mod. coarse
Medium
Mod. fine
Basic Soil Textural Class Names
Sandy
Loamy sands
Sandy loam Fine sandy loam
Very fine sandy loam Loam
Silt loam Silt
Clay loam Sandy clay loam Silty clay loam
Sandy clay Silty clay Clay
Clayey soils
Fine


Although not indicated in the soil textural class, organic matter may be present in the soil. Organic matter is very active chemically, and in moderate quantities can alter a soils's physical properties, mostly to the better.
The different sized particles in a soil determine its physical peoperties. Particles in a sand lie close together, creating few, large pores. This arrangement contributes to good aeration, drainage, permeability, and rapid infiltration of water. The chemical inactivity in a sand contributes to lew water-holding capacity and fertility. Conversely, particles in a clay lie together loosely, surrounded by numerous, small voids. Clays tend to have poor aeration, drainage, permeability, and slew infiltration; yet have high waterholding capacity and fertility. (27) Figure 2. sunmarizes these properties.
The processes of erosion and compaction are directly influenced by a soil's texture.
Figure 2. Properties of sand and clay.
Sand
good drainage good aeration good pemeability fast infiltration low water-holding low fertility
Clay
poor drainage poor aeration poor permeability slow infiltration high water-holding high fertility


Soil Erosion by Water
Soil erosion caused by rainfall is a function of several factors: intensity and duration of storms, amount of debris or vegetative cover, degree and length of slope, and texture of the soil. (27) The erosion process begins when a raindrop hits the ground. If there is litter or vegetation growing, this cover absorbs the physical impact of the raindrop, prior to contact with the soil. If there is no cover, the physical force of a raindrop's impact disperses fines on the soil surface. Very fine sand is the most easily dispersed, followed by clay and silt. Clay particles, being highly active chemically, tend to bond to each other, as well as to silt and sand. Strong aggregates of clay can form in a soil's structure which are quite resistant to dispersion. (28) Once dispersed, however, clay particles flew into and clog soil pores, rendering the soil surface impervious to infiltration. (28)
After hitting the ground, the raindrop infiltrates the soil surface and moves down through the soil. The speed at which water enters the soil (its infiltration rate), the ease with which water moves dewn through the soil (its permeability), and slope, together determine the amount of rainfall absorbed.
Rainfall not absorbed runs dcwnslope, carrying any dispersed fines. Water's mechanical ability of transport is proportional to its velocity. (34) Only fine particles can be moved at low velocities, while very huge boulders can be moved at very high velocities. The velocity of water flowing dcwnslope increases with the degree and length of slope. (34) Therefore, very fine sand, clay, and silt can be carried much further than can sand or gravel.
24


Soil erosion potential can be determined by use of the Universal Soil Loss Equation. The USLE was developed by Wischmeier in 1965 to determine potential amounts of soil lost to water erosion. (27) The equation quantifies the physical factors of storm damage and land resistance as they influence amount of soil lost in runoff. Hie Universal Soil Loss Equation is:
A = RxKxLxSxCxP
where: A = soil loss (tons per acre)
R = the soil erosivity index (erosivity of storms)
K = the soil erodibility index L = the hillslope-length factor S = the hillslope-gradient factor C = the cropping-management factor P = the erosion-control practice factor
Soil Compaction
The degree to which a soil will compact is a function of how close together its particles are and the amount of water present. The compaction of a soil is expressed as its bulk density. Bulk density is a measure of weight per unit volume of a soil. (27) In a coarse textured soil, such as mostly sand, the large particles cure pulled close together under their own weight. These coarse soils have a high bulk density. Conversely, the clay particles of a fine textured soil have a lower bulk density than coarse soils. Under applied loading, however, fine particles rearrange, and due to their platy shape, can become much more densely packed than can coarse particles under the same pressure. (27) The addition of water to a fine textured soil lubricates and loosens the arrangement of clay particles, causing them to become partially aligned. Under loading the clay particles in these wet soils compact further, and much more readily, than when they are dry. Figure 3. illustrates the range of bulk density and compactness of differently textured soils. (27)
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Figure 3. Bulk Density of Soils.
LANDFORM
Relative positions on a well developed hillslope are depicted in Figure 4. (38) They are: the surtmit of the hill or ridge; the shoulder, which lies just downhill of the surtmit and before the slope of the hill begins to steepen; the backslcpe, which is the steepest part of the hill; the footslope, where the slope of the hill begins to flatten out; the toeslope, which is the transition between the footslope and the valey bottom; an the valley bottom, which is the flattest land between two hills.
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Fig ire 4. Hil1 slope Positions. From Geomorphology by Ruhe.
As a very general trend, differences in soil texture and moisture are related to hillslope position. (38, 42) Soils of a locale tend to be very similar throughout due to similarity of underlying geology. However, seme differences in texture are likely to be found between the summit and toeslope of a hillslope. (38) In Colorado, many ridges have sandstone intrusions toward the summits and shale intrusions nearer the toeslopes. (42) Sandstones weather to coarser soils and shales weather to finer or clayeyer soils. (42) In addition, the weathering process accentuates this difference. Fines from the higher positions on a slope are carried downhill in runoff and deposited at the foot of the slope. Being more level there, moisture takes longer to dry up and continues to weather the soil fragments further into finer particles. (38) In general, soils nearer the summit of a hillslope tend to be coarser than at lower positions. (42) Finer soils may typically be found on the more level terrain of a toeslope or valley bottom. However, due to irregularities of topography, parent materials, and weathering, any texture of soil may appear anywhere on a hillslope. (42)
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SOIL MOISTURE REGIMES
Texture of a soil as it relates to infiltration and permeability partially determines the moisture content of that soil. In general, sands have higher infiltration rates than do loams or clays. (27, 28) Other factors determining the soil moisture regime of a location are aspect, wind, precipitation, and underlying geological features. (29) The steeper the slope, the less water infiltrates and the more runs off. Sncw accumulating on southerly and westerly aspects melts faster than on northerly or easterly aspects due to the direct rays of the sun. Soil in areas exposed to the wind dry out faster from evaporation.
Plant associations occur in particular habitats partly in response to the moisture regime provided there. (29, 23, 24) In general, dry plant associations tend to occur: on exposed and windy sites, where little snow accumulates or blows off early, coarse soils, steep grades, and south or west aspects. Conversely, moist plant associations tend to occur: on protected sites, where snow accumulates or stays longer, finer soils, gentler grades, and north or east aspects. Wet plant associations tend to occur where the water table is near the ground surface, on poorly drained sites, and where sncwmelt runoff inundates the ground for prolonged periods. (25)
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SBCTICN VI - Finding Overall Trampling Resistance and Trail location Suitability
The key to most suitable trail locations lies in determining landscape types which are most resistant to the effects of trampling. This involves analysis of the trail surface itself - of the soils and trail grades, as well as the trail margins - or the surrounding vegetation. The following process was used to determine trampling resistance and then trail location suitability.
Resistance of Trail Surfaces
Resistance of trail surfaces was determined by analysis of soil texture and trail grade as they relate to soil erosion.
SOIL RESISTANCE TO EROSION
Resistance to soil erosion was determined by use of the Universal Soil Loss Equation. The equation is:
A=RxKxLxSxCxP
where:
A = soil loss (tons per acre)
R = the soil erosivity index (erosivity of storms) K = the soil erodibility index L = the hillslope-length factor S = the hillslope-gradient factor C = the cropping-management factor P = the erosion-control practice factor.
This study looks at the variables of soil erodability - K, and hillslope length and grade - L/S. All other factors - storm characteristics, crcpping-management, and erosion-control practice (R, C, and P respectively) - are considered constants which do not affect the soil erodability of wilderness trails because of extremely low management intervention in the wilderness setting. K values (soil erodibility) have been established by the Soil
29


Conservation Service. (43) K values reflect a soil's infiltration rate, permeability, and structural stability, which in turn determine the soil's erodibility. K values are assigned to soil textures as follows:
sands .15 - .17
sandy loams .20 - • .24
clays .24
clay loams .28
silt loams .32
The K value used tor sand was .16, and .22 was used for sandy loam. The L/S value is the combined effect of slope grade and length. For this study, the arbitrary trail grades selected were: 3%, 6%, 9%, 12%, 15%, 20%, and 30%. Trail slope length was selected to be 100 feet. Values for these various trail slope grade/lengths were read fran the L/S chart which follows and are: 3% - .03; 6% -.065; 9% - 1.20; 12% - 1.75; 15% - 2.50; 20% - 4.0; 30% - 7.5. (34)
Figure 15-19 Chart for evaluating the length-slope factor, LS, in the Universal Soil-Loss Equation. The solid lines represent conditions within the range of data from which the curves were derived. The dashed lines are based on extrapolations and should be used unth (Fmm II ‘s Soil Conservation Service 1975b.)


As per the USLE, K values and L/S values were multiplied. Their sums indicate relative erodibility of trails on different soil textures and of different grades. See Table 1.
Table 1. K and L/S Sums
sandy loams/ sandy clay silt
sands loams clays loams loams
K value .16 .22 .24 .28 .32 Grade
L/S value
.03 .0048 .0066 .0072 .0084 .0096 3%
.065 .0104 .0143 .0156 .0182 .0208 6%
1.20 .1920 .2640 .2880 .3360 .3840 9%
1.75 .2800 .3850 .4200 .4900 .5600 12%
2.50 .4000 .5500 .6000 .7000 .8000 15%
4.0 .6400 .8800 .9600 1.1200 1.2800 20%
7.5 1.2000 1.6500 1.8000 2.1000 2.4000 30%
30% @
14.0 2.2400 3.0800 3.3600 .3.9200 4.4800 300'
17.0 2.7200 3.7400 4.0800 4.7600 5.4400 500'
U.S. Forest Service trail grade and length guidelines were included for comparison. The Forest Service recommends trail lengths of 100', 300', and 500' on 30% grades for trails of increasing difficulty, suitable for wilderness applications. (36) Lowest sums represent highest resistance to erosion. For comparison, grades and soil texture were listed in order of resistance to erosion from lowest sum to highest. See Table 2.
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Table 2. Rank Soil Ranking by Sums Grade Texture Sum L/S K
1 3% sands .0048 .03 .16
2 3% sandy loams .0066 .03 .22
3 3% clays .0072 .03 .24
4 3% clay loams .0084 .03 .28
5 3% silt loams .0096 .03 .32
6 6% sands .0104 .065 .16
7 6% sandy loams .0143 .065 .22
8 6% clays .0156 .065 .24
9 6% clay loams .0182 .065 .28
10 6% silt loams .0208 .065 .32
11 9% sands .1920 1.20 .16
12 9% sandy loams .2640 1.20 .22
13 12% sands .2800 1.75 .16
14 9% clays .2880 1.20 .24
15 9% clay loams .3360 1.20 .28
16 9% silt loams .3840 1.20 .32
17 12% sandy loams .3850 1.75 .22
18 15% sands .4000 2.50 .16
19 12% clays .4200 1.75 .24
20 12% clay loams .4900 1.75 .28
21 15% sandy loams .5500 2.50 .22
22 12% silt loams .5600 1.75 .32
23 15% clays .6000 2.50 .24
24 20% sands .6400 4.00 .16
25 15% clay loams .7000 2.50 .28
26 15% silt loams .8000 2.50 .32
27 20% sandy loams .8800 4.00 .22
28 20% clays .9600 4.00 .24
29 20% clay loams 1.1200 4.00 .28
30 30% sands 1.2000 7.50 .16
31 20% silt loams 1.2900 4.00 .32
32 30% sandy loams 1.6500 7.50 .22
33 30% clays 1.8000 7.50 .24
34 30% clay loams 2.1000 7.50 .28
35 30% silty loams 2.4000 7.50 .32
1 300' sands 2.2400 14.00 .16
2 500' sands 2.7200 17.00 .16
3 300' sandy loams 3.0800 14.00 .22
4 300' clays 3.3600 14.00 .24
5 500' sandy loams 3.7400 17.00 .22
6 300' clay loams 3.9200 14.00 .28
7 500’ clays 4.0800 17.00 .24
8 300' silt loams 4.4800 14.00 .32
9 500' clay loams 4.7600 17.00 .28
10 500’ silt loams 5.4400 17.00 .32
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TRENDS IN EROSION RATES
Sums of the K and L/S values were then plotted on a graph to determine trends in the change in rates of erosion. See Figure 5. As expected, each incremental increase in grade produced an increase in the rate of erosion. Three general trends emerged. Rates increased slowly but steadily up to 9%, at which point the curve started to increase rapidly. Nine to twelve percent grades are a transition stage, the beginning of a dramatic increase in the curve. The high resistance of the coarser soil textures relative to finer textures is illustrated in this part of the curve. Note that a sand on 12% grade is slightly more resistant than a clay, and considerably more resistant than a clay loam or silt loam on a 9% grade. Note the very slight difference in erodability between 9% silt loam, 12% sandy loam, and 15% sand. This trend of sands and sandy loams shewing higher relative resistance to the finer textures continues throughout the curve. However, nowhere else is the discrepancy so great as it is in the 9 - 12% range. At 12% the curve begins to rise very sharply, and at about 30%, skyrockets. Note that even at 30% grade, a 300-foot stretch or trail on sandy soil is still more resistant than a 100-foot stretch of trail on a silty loam. Erosion resistance of all soil textures on grades above 12% is extremely lew relative to the gentle grades, by as much as a thousandfold.
The Forest Service reccrrmends wilderness trail grades of 30% for stretches of 100', 300', and 500' for standards of increasing difficulty. (36) These are very steep trails which cut at sharp angles to the contours. Calculations for erodability on these trail scenarios were included for comparison. Note that these trails are ten to twenty times more erodable than a 100-foot trail stretch on 12% sand. Clearly these trails pose a maintenance problem if used
33


extensively. It is this author's opinion that there is no need to provide such erodable trails on soil when 30% ascents can be made over rock.
TRAIL GRADES - RESISTANCE TO EROSION
From the graph, relative resistance to erosion was noted as follows:
highest be lew 3%
high to moderate 3% - 6%
moderate 6% - 9%
low 9% - 12%
extremely low 12% - 30% and above
These levels of resistance form the ranking of trail grades and soil textures to be combined with vegetative resistance later on. See Table 3.
Table 3. Soil Resistance to Erosion on Trails
SOIL TEXTURE TRAIL GRADE TRAIL SLOPE LENGTH
Highest Resistance
sands 0% 100
sandy loams 0% II
clays 0% II
clay loams 0% II
silt loams 0% II
Hiqh to Moderate Resistance
sands 3%
sandy loams 3%
clays 3%
clay loams 3%
silt loams 3%
sands 6%
100'
II
•l


Table 3. continued
SOIL TEXTURE
TRAIL GRADE TRAIL SLOPE LENGTH
Moderate Resistance
sandy loams 6% II
clays 6% II
clay loams 6% It
silt loams 6% II
sands 9% II
Low Resistance
sandy loams 9% II
sands 12% II
clays 9% II
clay loams 9% II
silt loams 9% II
sandy loams 12% II
sands 15% 11
clays 12% II
Extremely Lew Resistance
clay loams 12% II
sandy loams 15% II
silt loams 12% II
clays 15% 11
sands 20% II
clay loams 15% 11
silt loams 15% II
sandy loams 20% II
clays 20% 11
clay loams 20% II
sands 30% 11
silt loams 20% II
sandy loams 30% II
clays 30% II
clay loams 30% II
silt loams 30% n
SOIL TEXTURE SLOPE LENGTH SLOPE GRADE
sands 300' 30'
sands 500’ It
sandy loams 300' II
clays 300' It
sandy loams 500' 11
clay loams 300' 11
clays 500' II
silt loams 300' II
clay loams 500' II
silt loams 500’ II


Resistance of Trail Margins
Resistance of trail margins to trampling is determined by analyis of vegetative form and soil moisture.
VEGEIMTVE FORM
Resistance to Trampling Damage
Vegetative form partially determines resistance of a plant species to being killed by trampling. Research shows that certain morphological characteristics contribute to trampling resistance. They cure: renewal buds located at or belcw the ground surface, numerous basal steins and leaves rather than single stems with leaves arising fran that stem, folded leaves, and tough, thicker leaves rather than thin, delicate leaves. (6, 7, 33) Gramminoids are quite resistant to trampling, having multiple, basal stems and leaves, and renewal buds at the ground surface. Shrubs have fair resistance to trampling - having numerous basal stems and sane renewal buds at the ground surface. Many forbs are single stemmed with leaves arising fran the stem, and have renewal buds well above the ground surface. In general, forbs have poor resistance to trampling.
Potential to Spread into Margins
Vegetative form also indicates the potential of a species to spread vegetatively into denuded trail margins. Spreading or reproducing vegetatively has numerous advantages over sexual reproduction. Vegetative reproduction saves time, and can take place independently of outside vectors. (23, 29) Gramminoids tend to spread very readily and have a good potential to revegetate denuded trail margins. Sane shrubs and sane forbs spread readily, but many of both do not. Therefore, shrubs and forbs have only fair potential to revegetate denuded trail margins.
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Overall Suitability tor Trail Margins
Hie two attibutes of tranpllng resistance and potential to spread into denuded margins together give an overall suitability for trail margins. Gramminoids are best suited for trail margins, being highly resistant to trampling and spreading readily into denuded areas. Shrubs have fair resistance to trampling, fair ability to spread into denuded areas, and only fair suitability for trail margins. Forbs are quite unsuitable for trail margins, with poor resistance to trampling and only fair ability to spread into denuded areas. See Figure 6. for the ranking of these vegetative forms.
Figure 6. Vegetative Form - Trail Margin Suitability.
Vegetative Qualities Vegetative Form
Gramminoid Shrub Forb
Resistance to Trampling Good Fair Poor
Potential to Spread into Margins Good Fair Fair
Overall Rating Good Fair Poor
Suitability for Trail Margins Best Fair Unsuitable
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SOIL MOISTURE
Research on wilderness trail conditions shows that soil moisture content and moisture regime of a species’ habitat directly affects its resistance to trampling. ((3, 6, 7, 8, 9, 22, 33) Trails going through dry meadows or open forests showed less damage to trampling than trails through shady, moist, and closed forests with lush forb understories. (3, 6, 7) Perhaps this resistance in the drier habitat plants is due to their lcwer water content, and therefore, less rigidity of tissues. The drier soil is better drained and so compacts less under trampling pressure. (27) The less compacted soil contributes to increased aeration and vigor of the plant's root system, as well as to better root penetration and spreading ability. (27, 28) Wet soils compact under loading, and experience breakdown of structure, making them completely unsuitable for trails.
TRAMPLING RESISTANCE
The combination of vegetative form and soil moisture regime together provide a plant ccmnunity with overall resistance to trampling. Dryness provides the most resistance, wetness the least, and moistness an intermediate value. See Figure 7.
Drainage Vegetative Form Gram | Shrub | Fort} | Gram | Shrub | Forb | Gram | Shrub | Forb
Very Good Dry Meadows & Forests HIGH
Good - Mod Moist Meadows & Forests MEDIUM
Poor Wet Meadows & Forests LOW


Note that very well-drained, dry meadows and open forests have highest resistance to trampling; well-drained, moist meadows and forests have medium resistance; and poorly drained, wet meadows and forests have low resistance.
SUITABILITY FOR TRAIL LOCATION
To determine suitability tor trail location, the vegetative form/moisture regimes are ranked for overall suitability for trail location. See Figure 8. Note that all torb and wet associations are unsuitable. A preference for dry associations over moist was iirplemented due to a tendancy for drier associations to occur on coarser soils. These coarser soils have a higher resistance to erosion and compaction. (27, 28) Thus, very well-drained, dry granminoid camrunities have highest suitability for trail location. Second best are dry shrub camrunities, followed by moist gramminoid camrunities, and then moist shrub camrunities. Figure 8. serves as a model for trail location suitability. Plant associations of any region or locale can be used with this model to indicate their relative resistances to trampling and trail location suitabilities.
Figure 8. Trampling Resistance Model.
Drainage Vegetative Form Gram | Shrub ] Fort) | Gram | 8hrub | Fort) Gram | Shrub | lorb
Very Good Dry ! ! 1 2 j | 1 1
Good - Mod * J Moist ! 3 4 ! | 1 1 1
Poor 1 1 ® 1 a Unsuitable | = 1 1 1
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Plant associations of Colorado coniferous forests were inserted into their appropriate positions in the model, and thus, received ranking of their individual resistances to trampling and trail location suitabilties. See Figure
9. The plant associations are coded by botanic name, using the first two letters of genus and species. (26) Capitalized letters indicate overstory tree species, and lower case letters indicate dominant understory species. For example: ABLA-PIEN caro stands tor Abies lasiocarpa-Picea englemannii overstory with Car ex rossii understory. The cannon name for this plant association is subalpine fir-Englemann spruce/ross sedge. A list of Colorado conifer forest plant associations ranked for trail suitability appears in Appendix III.
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Landform and Trail Grade
In general, trails of various grades are more likely to occur on particular hillslope positions. For example, trails with grades of under 3% are most likely to be on nearly level ground, such as a summit, toeslope, or valley bottan. Trails with grades of 20% must be on a back slope. Therefore, a general correlation can be drawn between possible trail grade and relative position on a hillslope. Figure 10. depicts most probable trail grades on relative hillslope positions. The range of trail grades are those which were selected to calculate soil loss. As expected, the location of trails with highest resistance to erosion would most likely be valleys, toeslopes, and summits. Footslopes and shoulders would likely have high to moderate resistance to erosion, and backslopes moderate to low resistance to erosion.
Figure 10. Trail Grades/Hillslope Positions.
Probable Trail Grades
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Scale of Trail Location Suitability
To identity most suitable trail locations on a hillslope, trail grades and hillslope positions are combined with the model of resistant plant association types. The combinations are ranked for suitability, incorporating a preference to dryness over moistness. See Figure 11.
Hillslope Position/ Trail Grade Vegetative F Dry Gramminoid orm Dry Shrub Moist Gramminoid Moist Shrub
Summit Toeslope 0% - 3% Valley 1 2 5 6
Shoulder 3% 6% Footslope 3 4 7 8
Backslope 6% - 12% 9 10 11 12
The result ot this final ranking is the establishment of an overall scale of suitability for trail locations. The scale is as follows in decreasing order of suitability.


SCALE OF TRAIL LOCATION SUITABILITY
Most Suitable
1. 0% - 3% trails on surrmits, toeslopes, and valley bottans with dry gramminoid plant associations
2. 0% - 3% trails on summits, toeslopes, and valley bottans with dry shrub plant associations
3. 3% - 6% trails on shoulders and footslopes with dry gramninoid plant associations
4. 3% - 6% trails on shoulders and footslopes with dry shrub plant associations
5. 0% - 3% trails on summits, toeslopes, and valley bottans with moist gramminoid plant associations
6. 0% - 3% trails on summits, toeslopes, and valley bottans with moist shrub plant associations
7. 3% - 6% trails on shoulders and footslopes with moist granminoid plant associations
8. 3% - 6% trails on shoulders and footslopes with moist shrub plant associations
9. 6% - 9% trails on backslopes with dry gramminoid plant associations
10. 6% - 9% trails on backslopes with dry shrub gramminoid plant associations
11. 6% - 9% trails on backslopes with moist granminoid plant associations
12. 6% - 9% trails on backslopes with moist shrub plant associations
Least Suitable
Field Descriptions of Scale Locations SUITABLE LOCATIONS
1. & 2. Nearly level, dry meadows or open forests with granminoid or shrub understories
Areas most suitable tor trail location are nearly level and dry. locations are typically on exposed ridges or mesa summits, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. These are areas of lew snow accumulation or where snow blows off early in the spring. The soils
43


here are very well drained with a relatively lew moisture content. They tend to range fran rocky or gravelly soils to coarse loams. To minimize erosion, trails located in these areas should not exceed 3%.
3. & 4. Gently sloping, dry meadows or open forests with grantninoid or shrub understories
The second most suitable areas for trail location have very gentle slopes and are dry. Locations are typically on exposed ridge and mesa summits or shoulders, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. These are areas of low snew accumulation or where snow blows oft early in the spring. The soils here are very well drained with a relatively low moisture content. They tend to range fran rocky or gravelly soils to coarse loams. To minimize erosion, trails located in these areas should not exceed 6%.
5. & 6. Nearly level, moist meadews or forests with grantninoid or shrub understories
The third most suitable locations tor trails are nearly level and relatively moist. These may be protected ridge summits, toeslopes or valley bottoms. Typical locations my be streamsides, lake margins, draws, benches, or meadews. Also included are areas protected fran extreme sun or wind. Aspect may be northerly to easterly, especially where little snow accumulates; or southerly to southwesterly where snow tends to accumulate. Soils are well drained and tend to range iron gravelly and sandy loams to sandy clays. To minimize erosion in these areas, trail slopes should not exceed 3%.
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7. & 8. Gently sloping, moist meadcws or forests with grairminoid or shrub
understories
Hie fourth most suitable trail locations for trails are gently sloping and relatively moist. These may be protected ridge summits or shoulders, or footslopes. Typical locations may be streamsides, draws, benches, or meadows. Also included are areas protected from extreme sun or wind. Aspect may be northerly to easterly, expecially where little snow accumulates, or southerly to southwesterly where snow tends to accumulate. Soils are well drained and tend to range from gravelly and sandy loams to sandy clays. To minimize erosion in these areas, trail slopes should not exceed 6%.
9. & 10. Sloping, dry meadows or open forests with gramminoid or shrub understories.
The fifth best locations for trails are moderately sloping and dry. These are backslopes and draws. Typical locations may be exposed or windswept slopes and may tend to have a southerly to westerly aspect. These are areas of lew snow accumulation or where snow blows off early in the spring. The soils here are very well drained with a relatively lew moisture content. They tend to range from rocky or gravelly to coarse loams. To minimize erosion, trails located in these areas should not exceed 12%.
11. & 12. Sloping, moist meadows or open forests with granminoid or shrub understories
The sixth most suitable locations for trails are moderately sloping and moist. These are backslopes and draws. Typical loactions may be northerly or easterly
45


slopes and draws where little snow accumulates, or southerly to westerly slopes and draws where sncw tends to accumulate. These are areas protected from extreme wind descication. Soils are well drained and tend to range from rocky and coarse loams to finer loams. To minimize erosion, trails located in these areas should not exceed 12%.
UNSUITABLE LOCATIONS FOR TRAILS
A. Steep trail grades and extended slope lengths
Steep slopes or terrain which requires trail slopes to exceed 12% for prolonged stretches are unsuitable due to excessive soil erosion. Erosion increases with both grade and slope length. On trails of 12% slope and steeper, maintained for 100', erosion increases dramatically. Trails may be located on slopes which are greater than 12%, but the slope of the trail should not exceed 12%.
B. Wet sites
Wet sites are unsuitable due to the extremely low resistance of the soil and vegetation to trampling. Trampling on a saturated soil compacts it and destroys its structure. This diminishes the soil's resistance to erosion as well as decreases ease of root penetration. In addition, plants growing in saturated conditions tend to have a high water content in their tissues, and thus are very likely to be broken upon trampling.
46


C. Forb-daninated understories
Forb understories are unsuitable due to the low trampling resistance of the vegetative form of many torbs. Many forbs have single stems with leaves arising from the stem. This form has been noted to be the least resistant to trampling.
Guidelines
Guidelines are drawn up trcm the preceeding scale of trail suitability.
Although derived exclusively trcm landscape resistance to trampling, these guidelines also incorporate an element of user experience. The guidelines will assist the trail designer in locating trails for minimal trampling impact. The guidelines describe proceedures for trail corridor identification which can be used on the drawing board and those which can be vised in the field. These guidelines appear in Section VI.
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PART II: CASE STUDY
The case study of this thesis applies the previously generated guidelines for minimum impact trail location to design a trail system on an actual site. The case study is Huston Park Wilderness Area, which is in the Medicine Bow National Forest of Wyoming. Huston Park was selected from many wilderness areas in Colorado and the immediate area. It was necessary to find a site which had its vegetation and soils mapped. At the time of this project, Huston Park had the most complete resource inventory of any wilderness area in Colorado or Wyoming.
The trail system of Huston Park was designed in two parts. First, the Continental Divide Trail corridor was designed. Second, the existing trail network was evaluated for its suitability of trail locations. Suitability of trail location was based on fragility of margin vegetation and erodability of trail soils. Any sections of trail on which the vegetation was determined to be too fragile or soils excessibely erodable were recommended to be revegetated.
General Background of the Area
The Medicine Bow mountain range extends from northern Colorado into southern Wyoming. Huston Park Wilderness Area is at the northern edge of the mountain range. Iaramie, Wyoming lies to the east, about 30 minutes by car. There are two highways in the vicinity. One runs north-south on the east edge of the Medicine Bows. The other cuts east-west through the mountain range just south of Huston Park. The Medicine Bows are a major recreation area for Laramie and the northern front range of Colorado.
Huston Park covers roughly 34,000 acres, and is about 12 miles by 4 miles in
48


dimension. The Wilderness Area encompasses a massive uplift caused by the Continental Divide as it winds through the area. Ihe Continental Divide is quite high in this area, but it is not rugged. Elevation of the area ranges from 8,600 feet at its western edge to 10,444 feet at the highest point on the Divide. Timberline occurs at about 10,200 feet in elevation, compared to 11,000 feet at Denver's lattitude. There is roughly 250 feet of land above timberline. The uplift is quite flat on top, forming a series of high elevation parks.
These are expansive grassy areas with clusters of tree islands.
The landform catches a considerable amount of precipitation, and the vegetation is relatively moist. The vegetation consists mainly of Englemann spruce and subalpine fir, with sane aspen and lodgepole pine. The top part of the uplift, being flat and wet, consists of extensive boggy areas dominated by wet forb associations. There are numerous small lakes scattered throughout the area.
The uplift forms the headwaters of several rivers, most notably the North Fork of the Encampment River.
The Continental Divide enters at the middle of the northern boundary, winds through the area in a southeasterly direction, and exits at the middle of the southern boundary. Several trails and stock driveways run through the site. A major trail runs east-west just south of the northern border. TVo trails run north-south through the area. One runs down the middle of the area and the other at about the eastern one third mark.
The Continental Divide Trail
The Continental Divide National Scenic Trail is a planned, but not yet designed, trail which will follow the Continental Divide through the United States from
49


the border with Canada to the border with Mexico. It will go through Montana, Wyaning, Colorado, and New Mexico through federal, state, and private lands. When built, the Continental Divide Trail will be the Rocky Mountain equivalent to the Pacific Coast Trail or the Appalachian Trail.
DESIGNING THE CONTINENTAL DIVIDE TRAIL
Ihe main design criteria for locating the Continental Divide Trail is that is must cane within two miles of the Continental Divide. An attempt was made to create as much variety along the trail as possible. The trail was designed to incorporate a variety of plant associations, hillslope positions, and grades.
MAPPING STAGE
Vegetation and soil data were obtained fran the Forest Service at the Hayden Ranger District in Encampment, Wyoming. Vegetation and soil maps were at the scale of 1:24000. All subsequent mapping and designing of the trail system was done at the same scale.
Vegetation
Plant associations were mapped using the ranking system frcm the guidelines.
Dry grairminoids were located in the southwest portion of the site. Dry shrubs occupy a sizeable area on the east border. Moist shrubs occur in scattered patches over the southern part of the site. Moist grairminoids cover the vast majority of the site. Wet forbs dominate a large area on the flat top of the site. Any new trails must avoid this boggy area.
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Soils
Finer loams occur in large patches or narrow fingers over the site. The majority of the site's finer soils occur on the flat uplift. Fingers of fine loam follow drainages uphill. These highly erodable soils will pose a constraint to trail grades.
Hillslope Position
Most of the leveler ground on the site is contained within the flat sunmit of the uplift. Very little area is considered flat bottomland. The hillslope position map emphasizes the topography and extent of the uplift.
Destination/Access
The site's numerous small lakes are probable destination points. Most of these lakes lie on or close to the flat area and within the summit of the uplift. The existing trails on the site are also potential destination points. Access is provided at eleven points around the boundary. The entire western boundary is delineated by a trail. The eastern boundary is formed by two roads. The eastern boundary is the site's major access point.
Constraints
The constraints to trail location were mapped as a composite map. Constraints included unsuitable plant associations, fine textured soils, destination and access points, hillslope positions, and the Continental Divide. Any trail must avoid unsuitable plant associations, and maintain a gentle grade over fine soils. The Continental Divide Trail must cane within two miles of the Continental Divide.
51


PLANNING STAGE
Creating Internal Circulation - Linking Destination Points As per the guidelines, the trail was first routed through suitable plant associations, linking the destination points. Due to the nature of the trail, it was determined that the most appropriate form it should take is a single linear trail linking its northern and southern access points, with short spurs as needed. The points where the Continental Divide enters and exits the site both became major destination and access points. Numerous small lakes became secondary destination points. The trail was routed to cane within 200 feet of nine lakes along its course. TWo spur trails provide access to 4 more lakes.
All of these lakes are in the higher elevations of the wilderness area.
The trail was designed to encompasses a variety of vegetation types. It goes through meadows, shrubland, open forest, and alpine meadow. It goes through moist gramminoid, moist shrub, and dry shrub oamiunities. For various stretches it skirts around lush boggy cattnunities.
Using Hillslope Positions
Second, circulation was designed to encompasses a variety of hillslope positions. The one hillslope position the trail lacks completely is a true bottomland. Due to the nature of the Continental Divide, it was impractical to route the trail out of the way to go down into a side valley. The trail does, however, criss-cross a major draw toward the south end of the area. Due to the nature of the site, and requirement to skirt the Continental Divide, the majority of the trail is along the summit of the uplift.
52


Checking Trail Grade Appropriateness on Soil Textures
Finally, the trail grades were checked to comply with the underlying soil textures. Hie great majority of the trail lays atop finer textured soils. Accordingly, the majority of the trail is under 6% in grade. Trail grades go up to 15% in the few, and widely spaced sections over rock or coarse soils.
Several major adjustments of the corridor were necessary to accomodate the underlying soils.
Locating the Centerline in the Field
The next step in locating the Continental Divide Trail would be to stake the actual centerline in the field. This planning process to locate the trail has successfully identified a corridor of maximum resistance to the impacts of trampling. Hie best final location can only be determined in the field, considering all surface conditions.
THE CONTINENTAL DIVIDE TRAIL SECTIONS
Hie Continental Divide Trail is made up of five sections, each with its own character. Hie trail is about 15 miles long and utilizes about 4 miles of existing trails. Hie sections are described belcw.
Section 1: Section 1 descends onto the site fran the northern boundary. This section of the trail is steep and utilizes an existing trail. Views of 2 major valleys are seen fran the higher portion of this section. Hie trail skirts along a rocky area before enterring a moist meadcw, and finally crosses the North Fork of the Encampment River. This section is on a backslope with trail
53


grades of 15%
Section 2; Section 2 picks up at the North Fork of the Encampment River and rises gently as it progresses southward and upward along the Continental Divide, until reaching the highest point in the area at 10,44 feet in elevation. This section of the trail stays within 200 feet of the Continental Divide along its entire length, and passes by four alpine lakes. The trail here is almost entirely above timberline. This is perhaps the most exciting stretch of trail due to its hillslope position. The trail here lies on the edge of the summit of the uplift, with the land dropping off steeply to the west. To the east is the vast boggy area of the uplift. Views frcm this stretch would be spectacular, particulary to the west. This section of the trail is almost entirely on finer loams, and trail grades are under 6%.
Section 3: Section 3 starts at the highest point and descends gradually in a southeasterly direction. The edge of the uplift is left behind as the trail crosses a high elevation park. Views fran this section are of mountains in the foreground with the plains beyond. This section of the trail passes by three small lakes with a spur to two more. Trail grades are all under 6%.
Section 4: Section 4 starts out by crossing the Continental Divide and progress in a southerly direction. In this area the Divide becomes more of a defined ridge than a flat upland. Views from this section of the trail are into Colorado to the south. This section of the trail goes through more diverse vegetation than any other section. The primary difference is the dry shrubland which lies just east of the Continental Divide. TWo small lakes are passed with spurs to two more to the east. This section of the trail utilizes about two
54


miles of existing trail. Hie trail grades here are all under 6%.
Section 5; Section 5 leaves the Continental Divide, descends down into a steep draw, and climbs back up to exit the site. Ibis section of the trail passes alternately through meadows and shrubland in very wide switchbacks. Trail grades in this section range fran below 6% to 15%.
THE WIIDERNESS TRAIL SYSTEM
All existing sections of trail within the wilderness area were evaluated for their suitability of location. This evaluation was based on resistance to trampling as determined in this thesis. The criteria were appropriateness of trail grade on underlying soils and resistance of the vegetation to trampling. Vegetation types considered too fragile to serve as trail margins were forb-dcminated understories and poorly-drained boggy ccrrnunities. Trail grade and soil texture scenarios considered to have excessive erosion potential were trail grades over 6% on fine-textured soils, and grades over 15% on any soil type except very rocky soil. There are no very rocky soils within the wilderness area. Any sections of trail which were unsuitable were reccrmvended to be obliterated and revegetated. The sections of existing trails are evaluated belcw:
Section A: Trail grades on Section A are appropriate to the soils and this section should remain.
Section B: Trail grades on Section B range between 20% and 30%. These
55


grades are too steep and likely to cause severe erosion problems. Section B should be revegetated.
Section C: Trail grades on Section C are all appropriate to the soils.
This section barely skirts the unsuitable boggy vegetation along the North Fork of the Encampment River. This section should remain.
Section D: Section D goes through the unsuitable boggy vegetation of the
uplift and should be revegetated. This vegetation is too fragile to support a trail.
Section E: Trail grades on Section E are appropriate to the soils and this section should remain.
Section F: Trail grades on Section F are appropriate to the soils and this
section should remain. This section forms part of the Continental Divide Trail.
Section G: Trail grades on Section G are appropriate to the soils and this section should remain.
Section H: Most of the trail grades on Section H are close to 15% and are too steep for the fine-textured soils. This section should be revegetated.
Section J; Section J is a new access trail to the system. Most of the
56


wilderness' use caries from the east and no access trail already existed on that side. The trail links two dirt roads to the Continental Divide Trail. It was designed at grades under 6%.
CONCLUSION
The completed trail system as designed for Huston Park Wilderness Area would result in many changes to the existing situation. There would be 15 miles of new Continental Divide Trail, including 5 miles of new access trail. Ten of the twenty-one miles of existing trails would be revegetated. The likelihood of these changes taking place sire virtually non-existant due to the high cost of revegetation.
The existing trails which were evaluated to be obliterated are presently located in areas unsuitable for trails because of high soil erosion potential or easily damaged vegetation types. The proportion of those trails which are unsuitable is almost half. Therefore, in conclusion, it would seem that the original assumption of this thesis is proven to be true in the case of Huston Park Wilderness Area. The thesis assumption was that many existing trails in wilderness lands are located on land not resistant to trampling.
57


Appendix I. The Wilderness Act of 1964.
Wilderness Act
78 STAT. 890. 78STAT 891
Public law HK-577 8Sth G ingress, S. -i September 3, 1‘X>1
AN ACT
To establish a National Wilderness Preservation System for the permanent gtxxl of the whole people, and
for other purposes.
Be it enacted by the Senate and House of Representatives of the United States of America in Congress
assembled,
SHORT TITLE
SECTION 1. This Act may be cited as the "Wilderness Act".
WILDERNESS SYSTEM ESTABLISHED STATEMENT OF POIJCY
Sec. 2. (a) In order to assure that an increasing population, accompanied by expanding settlement and growing mechanization, does not occupy and modify all areas within the United States and its possessions, leaving no lands designated for preservation and protection in their natural condition, it is hereby declared to be the policy of the Gingrcss to secure for the American people of present and future generations the benefits of an enduring resource of wilderness. For this purpose there is hereby established a National Wilderness Preservation System to be composed of federally owned areas designated by Gingress as "wilderness areas", and these shall be administered for the use and enjoyment of the American people in such manner as will leave them unimpaired for future use and enjoyment as wilderness, and so as to provide for the protection of these areas, the preservation of their wilderness character, and for the gathering and dissemination of information regarding their use and enjoyment as wilderness; and no Federal lands shall be designated as "wilderness areas" except as provided for in this Act or by a subsequent Act.
(b) The inclusion of an area in the National Wilderness Preservation System notwithstanding, the area shall continue to be managed by the Department and agency having jurisdiction thereover immediately before its inclusion in the National Wilderness Preservation System unless otherwise provided by Act of Congress. No appropriation shall be available for the payment of expenses or salaries for the administration of the National Wilderness Preservation System as a separate unit nor shall any appropriations be available for additional personnel stated as being required solely for the purpose of managing or administering areas solely because they are included within the National Wilderness Preservation System.
DEFINITION OF WILDERNESS
(c) A wilderness, in contrast with those areas where man and his own works dominate the landscape, is hereby recognized as an area where the earth and its community of life are unrrammeled by man, where man himself is a visitor who does not remain. An area of wilderness is further defined to mean in chis Act an area of undeveloped Federal land retaining its primeval character and influence, without permanent improvements or human habitation, which is protected and managed so as to preserve its natural conditions and which (1) generally appears to have been affected primarily by the forces of nature, with the imprint of man's work substantially unnoticeable; (2) has outstanding opportunities for solitude or a primitive and unoonfined type of recreation; (3) has at least five thousand acres of land or is of sufficient size as to make practicabk- its preservation and use in an unimpaired condition; and (4) may also contain ecological, geological, or other features of scientific, educational, scenic, or historical value.
NATIONAL WILDERNESS PRESERVATION SYSTEM—EXTENT OF SYSTEM
Sec. 3- (a) All areas within the national forests classified at least 30 days before the effective date of this Aa by the Secretary of Agriculture or the Chief of the Forest Service as "wilderness", "wild", or "canoe" are hereby designated as wilderness areas. The Secretary of Agriculture shall—


(1) Within one year after the effective date of this Act, file a map and legal description of each wilderness area with the Interior and Insular Affairs Committees of the United States Senate and the House of Representatives, and such descriptions shall have the same force and effect as if included in this Act: Provided, bou it er. That correction of clerical and typographical errors in such legal descriptions and maps may be made.
(2) Maintain, available to the public, records pertaining to said wilderness areas, including maps and legal descriptions, copies of regulations governing them, copies of public notices of, and reports submitted to Gingress regarding pending additions, eliminations, or modifications. Maps, legal descriptions, and regulations pertaining to wilderness areas within their respective jurisdictions also shall be available to the public in the offices of regional foresters, national forest supervisors, and forest rangers
(b) The Secretary of Agriculture shall, within ten years after the enactment of this Act, review, as to its suitability or nonsuitability for preservation as wilderness, each area in the national forests classified on the effective date of this Act by the Secretary of Agriculture or the Chief of the Forest Service as "primitive" and report his findings to the President. The President shall advise the United States Senate and House of Representatives of his recommendations with res pea to the designation as "wilderness” or other reclassification of each area on which review has been completed, together with maps and a definition of boundaries. Such advice shall be given with respea to not less than one-thind of all the areas now classified as "primitive” within three years after the enactment of this Act, not less than two-thirds within seven years after the enactment of this Act, and the remaining areas within ten years after the enactment of this Act. Each recommendation of the President for designation as "wilderness” shall become effective only if so provided by an Act of Gingress Areas classified as "primitive" on the effective date of this Act shall continue to be administered under the rules and regulations affecting such areas on the effective date of this Act until Gingress has determined otherwise. Arty such area may be increased in size by the President at the time he submits his recommendations to the Gxigress by not more than five thousand acres with no more than one thousand two hundred and eighty acres of such increase in any one compact unit; if it is proposed to increase the size of any such area by more than five thousand acres or by more than one thousand two hundred and eighty acres in any one compact unit the increase in size shall not become effective until acted upon by Gingress. Nothing herein contained shall limit the President in proposing, as pan of his recommendations to Congress, the alteration of existing boundaries of primitive areas or recommending the addition of any contiguous area of national forest lands predominandy of wilderness value. Notwithstanding any other provisions of this Act, the Secretary of Agriculture may complete his review and delete such area as may be necessary, but not to exceed seven thousand acres, from the southern tipof the Gore Range-Eagles Nest Primitive Area, Colorado, if the Secretary determines that such action is in the public interest.
(c) Within ten years after the effective date of this Act the Secretary of the Interior shall review every roadless area of five thousand contiguous acres or more in the national parks, monuments and other units of the national park system and every such area of, and every roadless island within, the national wildlife refuges and game ranges, under his jurisdiction on the effective date of this Act and shall report to the President his recommendation as to the suitability or nonsuitability of each sudi area or island for preservation as wilderness The President shall advise the President of the Senate and the Speaker of the House of Representatives of his recommendation with respect to the designation as wilderness of each such area or island on which review has been completed, together with a map thereof and a definition of its boundaries Such advice shall be given with respect to not less than one-third of the areas and islands to be reviewed under this subsection within three years after enactment of this Act, not less than two-thirds within seven years of enactment of this Act, and the remainder within ten years of enactment of this Act. A recommendation of the President for designation as wilderness shall become effective only if so provided by an Act of Gingress. Nothing contained herein shall, by implication or otherwise, be construed to lessen the present statutory authority of the Secretary of the Interior with respect to the maintenance of roadless areas within units of the national park system.
(d) (1) The Secretary of Agriculture and the Secretary of the Interior shall, prior to submitting any recommendations to the President with respect to the suitability of any area for preservation as wilderness—
(A) give such public notice of the proposed action as they deem appropriate, induding publication in the Federal Register and in a newspaper having general circulation in the area or areas in the vicinity of the affected land;
(B) hold a public hearing or hearings ar a kxation or locations convenient to the area affected The hearings shall be announced through such means as the respective Secretaries involved deem appropriate, including notices in the Federal Register and in newspapers of general circulation in the
Class if cation
Presidential recummenda-tion to Congress
Congressional approval
78STAT 891 78 bTAT. 892
Report to President.
Presidential recommendation to Congress
Congressional approval.
Suitability
Publication in Federal Register
Hearings
PiWication in Federal Register


30 30
79 STAT m2. 7H STAT 89V
Proposal modification.
area: Pmt *Jed, That if the lands invt lived are located in more than one State, at least one hearing shall be held in each State in which a portion of the land lies;
(C) at least thirty days before the date of a hearing advise the Governor of each State and the governing board of each county, or in Alaska the borough, in which the lands are located, and Federal departments and agencies concerned, and invite such officials and Federal agencies to submit their views on the proposed action at the hearing or by no later than thirty days following the date of the hearing.
(2) Any views submitted to the appropriate Secretary under the provisions of (1) of this subsection with respect to any area shall be included with arty recommendations to the President and to Congress with respect to such area
(e) Any modification or adjustment of boundaries of any wilderness area shall be recommended ty the appropriate Secretary after public notice of such proposal and public hearing or hearings as provided in subsection (d) of this section. The proposed modification or adjustment shall then be recommended with map and description thereof to the President The President shall advise the United States Senate and the Ffouse of Representatives of his recommendations with respect to such modification or adjustment and such recommendations shall become effective only in the same manner as provided for in subsections (b) and (c) of this section.
16 USC 47V 16 USC 528-541
16 USC 577.577b,
16 USC 577c-577h 16 USC 577d-L 577*1, 577h
49 Slat 545.
16 USC 1 et /e 41 Sat. 1064. 49 Star 848
STAT 894. STAT 894
USE OF WILDERNESS AREAS
Sec 4 (a) The purposes of this An are hereby declared to be within and supplemental to the purposes for which national forests and units of the national park and national wildlife refuge systems are established and administered and—
(1) Nothing in this Act shall be deemed to be in interference with the purpose for which national forests are established as set forth in the Act of June 4 1897 (30 Stat. 11), and the Multiple-Use Sustained-Yield Act of June 12, 1960 (74 Stat. 215).
(2) Nothing in this Act shall modify the restrictions and provisions of the Shipstead-Nolan Act (Public Law 539, Seventy-first Congress, July 10,1930; 46 Stat. 1020), the Thye-Blatnik Act (Public Law 733, Eightieth Congress, June 22, 1948; 62 Stat 568), and the Humphrey-Thye-Blatnik-Andersen Act (Public Law 607, Eighty-fourth Congress, June 22,1956; 70 Stat. 326), as applying to the Superior National Forest or the regulations of the Secretary of Agriculture.
(3) Nothing in this Act shall modify the statutory authority under which units of the national park system are created. Further, the designation of any area of any park, monument, or other unit of the national park system as a wilderness area pursuant ® this Act shall in no manner lower the standards evolved for the use and preservation of such park, monument, or other unit of the national park system in accordance with the Act of August 25,1916, the statutory authority under which the area was created, or any other Act of Congress which might pertain to or affect such area, including, but not limited to, the Act of June 8, 1906 (34 Stat 225; 16 US.C 432 et seq.); section 3(2) of the Federal Power Act (16 US.C 796(2)); and the Act of August 21,1935 (49 Stat 666; 16 US.C 461 et seq.).
(b) Except as otherwise provided in this Act, each agency administering any area designated as wilderness shall be responsible for preserving the wilderness character of the area and shall so administer such area for such other purposes for which it may have been established as also to preserve its wilderness character. Except as otherwise provided in this Act, wilderness areas shall be devoted to the public purposes of recreational, sceruc, scientific, educational, conservation, and historical use.
PROHIBITION OF CERTAIN USES
(c) Except as specifically provided for in this Act, and subject ® existing private rights, there shall be no commercial enterprise and no permanent road within any wilderness area designated by this Act and, except as necessary » meet minimum requirements for the administration of the area for the purpose of this Act (including measures required in emergencies involving the health and safety of persons within the area), there shall be no temporary road, no use of motor vehicles, mororized equipment or motorboats, no landing of aircraft, no other form of mechanical transport, and no structure or installation within any such area.
SPECIAL PROVISIONS
(d) The following special provisions are hereby made:
(1) Within wilderness areas designated by this Act the use of aircraft or mo®rboats, where these uses have already become established, may be permitted ® continue subject w such restrictions as the Secretary of Agriculture deems desirable. In addition, such measures may be taken as may be necessary in the control of fire, insects and diseases, subject to such conditions as the Secretary deems desirable


at St
Appendix I. The Wilderness Act of 1964.
Wikle-mcss Aa
STAT 8>1
l\iblK law HK-377 XMth Gingress, S. 1 September 3, 1061
AN ACT
To establish a National W'ikk-rntss Preservation System for the permanent gicnJof the whole people, atxl
for other purposes
Be it enacted by the Senate jW House of Representalhvs of the United States of America in Congress
assembled,
SHORT TITLE
SBenON 1 This Aa iTuy be cited as tire "Wilderness Aa".
WU.DiiRNT.SS SYSTEM ESTABLISHED STATEMENT OF BOIJCY
Sec 2. (a) In order to assure that an increasing population, accompanied by expanding settlement and growing mechanizatKin, docs not occupy and modify all areas within the United States and its pnssessKins, leaving no lands designated for preservation and proteaion in their natural condition, it is hereby declared to be the policy of the Gingress to secure for the American people of present and future generatKins the benefits of an enduring rev nine of wilderness For this purpose there is hereby established a National Wilderness Preservation System to be composed of federally owned areas designated by Gingress as "wilderness areas”, and these shall be administered for the use and enjoyment of the American people in such manner as will leave them unimpaired for future use and enjoyment as wilderness, and so as to provide for the protection of these areas, the preservation of their wilderness character, and for the gathering and dissemination of information regarding their use and enjoyment as wilderness; and no Federal Lands shall be designated as "wiklerness areas" except as provided for in this Aa or by a subsequent Aa
(b) The inclusion of an area in the NatKinal Wilderness Preservatkin System notwithstanding, the area shall continue to be managed by tlx- Department and agency having jurisdiakin thereover immediately before its inclusion in the National Wiklerness PreservatKin System unless otherwise provided by Aa of Congress. No appropriation shall be available for the payment of expenses or salaries for the administratxin of the National Wilderness Preservation System as a separate unit nor shall any appropriations be available for additional piersonncl stated as being required solely for the pxirpose of managing or administering areas solely because they are included within the Natxjnal Wilderness Preservation System
DEFINITION OF WILDERNESS
(c) A wiklerness, in contrast with those areas where man and his own works dominate the landscape, is hereby recognized as an area where the earth and its community of life are unrrammeled by man, where man himself is a visitor who does not remain An area of wilderness is further defined to mean in this Aa an area of undevekipxd Federal land retaining its pirimeval character and influence, without piermanent improvements or human habitatkin, which is protected and managed so as to preserve its natural cunditxins and which (1) generally appears to have been affected primarily by the fortes of nature, with the imprint of mans work substantially iinnotkeable; (2) has outstanding opportunities for solitude or a primitive and untonfined type of recreation; (3) has at least five thousand acres of land or is of sufficient size as to make pxacoaibk- its preservatRin and use in an unimpaired condition, and (-1) may also contain ecological, gtnkigical, or other tcumres of scientific, educ.itninal, scenx, or historical value
NATIONAL WIIJJEKNLSS RRESILRVATION SYSTEM — EXTENT OF SYSTEM
See 3. (a) All areas within tlx- national forests classihed at k-ast .30 days before the effective due of this Act by the Secretary of Agriculture or the Gix-f of the FLirest Serv ice as "wiklerness", "w ild", or "caixx" are Ixreby designated as wikk-rtxss areas The Secretary of Agriculture shall—


78 STAT 895. 78 STAT 896 (7) Nothing in this Aa shall constitute an express or implied claim or denial on the part of the Federal Government as to exemption from State water laws. (8) Nothing in this Aa shall be construed as affecting the jurisdiction or responsibilities of the several States with respect to wildlife and fish in the national forests. STATE AND PRIVATE LANDS WITHIN WILDERNESS AREAS
Transfers, restriction. SEC 5. (a) In any case where State-owned or privately owned land is completely surrounded by national forest lands within areas designated by this Aa as wilderness, such State or private owner shall be given such rights as may be necessary to assure adequate access to such State-owned or privately owned land by such State or private owner and their successors in interest, or the State-owned Land or privately owned land shall be exchanged for federally owned land in the same State of approximately equal value under authorities available to the Secretary of Agriculture: Provided, however. That the United States shall not transfer to a State or private owner any mineral interests unless the State or private owner relinquishes or
78 STAT. 896. causes to be relinquished to the United States the mineral interest in the surrounded land (b) In any case where valid mining claims or other valid occupancies are wholly within a designated national forest wilderness area, the Secretary of Agriculture shall, by reasonable regulations consistent with the preservation of the area as wilderness, permit ingress and egress to such surrounded areas by means which have been or are being customarily enjoyed with res pea to other such areas similarly situated
AttJUlSItKXl (c) Subjea to the appropriation of funds by Congress, the Secretary of Agriculture is authorized to acquire privately owned land within the perimeter of any area designated by this Aa as wilderness if (1) the owner concurs in such acquisition or (2) the acquisition is specifically authorized by Congress. GIFTS, BEQUESTS, AND CONTRIBUTIONS SEC & (a) The Secretary of Agriculture may accept gifts or bequests of land within wilderness areas designated by this Aa for preservation as wilderness. The Secretary of Agriculture may also aocepx gifts or bequests of land adjacent to wilderness areas designated by this Aa for preservation as wilderness if he has given sixty days advance notice thereof to the President of the Senate and the Speaker of the House of Representatives. Land accepted by the Secretary of Agriculture under this seaion shall become pan of the wilderness area involved. Regulations with regard to any such land may be in accordance with such agreements, consistent with the policy of this Aa, as are made at the time of such gift, or such conditions, consistent with such policy, as may be included in, and aocepted with, such bequest. (b) The Secretary of Agriculture or the Secretary of the Interior is authorized to accept private contributions and gifts to be used to further the purposes of this Act. ANNUAL REPORTS SEC 7. At the opening of each session of Congress, the Secretaries of Agriculture and Interior shall jointly report to the President for transmission to Congress on the status of the wilderness system, including a list and desaipitions of the areas in the system, regulations in effect, and other piertinent information, together with any recommendations they may care to make. Approved September 3, 1964. LEGISLATIVE HISTORY: HOUSE REPORTS: No. 1338 accompanying H. R. 9070 (Comm on Interior & Insular Affairs) and No. 1829 (Comm of Conference). SENATE REPORT No. 109 (Comm on Interior & Insular Affairs). CONGRESSIONAL RECORD. VoL 109 (1963): Apr. 4, 8, considered in Senate. Apr. 9, considered and passed Senate. VoL 110 (15>64): July 28, considered in House. July 30, considered and passed House, amended, in lieu of H. RSX)70. Aug. 20, House and Senate agreed to conference report
/


Appendix II. Wilderness Area Use
Table 3. Distribution of racraatlonal uaa and acraaga by classification status.
Percentage of Total Acres and Total Visitor-Days For All Areas and Agencies
Agency Wilderness Proposed Wilderness Primitive Areas' All Types
Forest Service
Acres 33.3 0 5.8 39.1
Visitor-days 47.5 0 5.6 53.1
National Park Service
Acres 6.7 36.3 0 43.0
Visitor-days 6.8 37.6 0 44.4
Fish and Wildlife Service
Acres 1.7 15.8 0 17.5
Visitor-days .9 1.3 0 2.2
Bureau of Land Management
Acres 0 0 .5 .5
Visitor-days 0 0 .3 .3
Percent of all areas
Acres 41.6 52.1 6.3 100
Visitor-days 55.1 39.0 5.9 100
•Primitive areas include those in the national forests and public lands administered by the Bureau of Land Management.
Table 4. Recreational use and miles of trail In National Wilderness Preserve System units (Forest Service and National Park Service only), by region (excluding Alaska and Hawaii).
Region Visitor-days' (no. (Vo)] Miles of Trail lno (Vo)] Visitor-days Per Mile of Trail
Northeast 88,300 79 1,117
(0.9) (0.4)
Midwest 1,067,100 1,835t 582
(11-8) (95)
South 966,700 1,023 945
(10.7) (4.6)
Rocky Mountain States 2,860,200 10,034 285
(31.6) (52.1)
Pacific States 4,067,800 6,420 634
(44.9) (33.4)
Total 9,050,100 19,343 468
(100) (100)
’Most units reported 1978 use data.
â– (Includes water in the Boundary Water and Canoe Area and portage routes


Appendix III. Colorado Conifer Forest Plant Associations - Suitability for Trail Location
The follcwing plant associations of Colorado conifer forests are grouped in order of resistance to trampling, from highest resistance to lowest resistance. The associations are listed by dominant overstory tree and dominant understory species.
Botanic Name
1. DRY GRAMMINOID ASSOCIATIONS Subalpine
Abies lasiocarpa-Picea englemanni/ Carex rossii
Pinus contorta/Carex rossii Pinus aristata/Festuca arizonica Pinus aristata/Festuca thurberi
Montane
Pseudotsuga menziesii/
Festuca arizonica Pinus ponderosa/Carex rossii Pinus ponderosa/Andropogon scoparius Pinus ponderosa/Festuca idahoensis Populus tremuloides/
Ceanothus velutinus
2. DRY SHRUB ASSOCIATIONS Subalpine
Abies lasiocarpa-Picea englemannii/ Juniperus ccmmunis
Pinus contorta/Arctostaphylos uva-ursi Pinus aristata/Ribes montigenum
Montane
Pseudotsuga menziesii/
Arctostaphylos uva-ursi Pseudotsuga menziesii/
Cercocarpus montanus Pseudotsuga menziesii/
Holodiscus dumoscus Pseudotsuga mensiesii/
Symphoricarpos oreophilus Pinus ponderosa-Pinus edulis/
Quercus gambelii
Abies concolor-Pseudotsuga menziesii/ Holodiscus dumoscus
Common Name
Subalpine fir-englemann spruce/ ross sedge
Lodgepole pine/ross sedge Bristlecone pine/Arizona fescue Bristlecone pine/Ihurber fescue
Douglas fir/
Arizona fescue Ponderosa pine/ross sedge Ponderosa pine/
Ponderosa pine/Idaho fescue Aspen/
Siicwbrush ceanothus
Subalpine fir-Englemann spruce/ ccrtmon juniper Lodgepole pineAinnikinnick Bristlecone pine/mountain current
Douglas fir/ kinnikinnick Douglas fir/
mountain mahogany Douglas fir/ ocean spray Douglas fir/
mountain sncwberry Ponderosa pine-Pinyon pine/ gambel oak
White fir-Douglas fir/ ocean spray


3. MOIST GRAMMINOID ASSOCIATIONS
Subalpine
Abies lasiocarpa/Carex geyeri Abies lasiocarpa-Picea englemannii/ Carex geyeri
Pinus contorta/Carex geyeri Montane
Picea pungens/poa
Picea pungens-Pseudotsuga menziesii/ Carex foenea
Picea pungens-Pseudotsuga menziesii/ Festuca arizonica
Pseudotsuga menziesii/Carex rossii Pseudotsuga menziesii/Carex geyeri Abies ooncolor-Pseudotsuga menziesii/ Festuca arizonica
Abies ooncolor-Pseudotsuga menziesii/ sparse
Pinus ponderosa/Carex heliophila Pinus ponderosa/Bouteloua gracilis Pinus ponderosa/Carex geyeri Pinus ponderosa/Hesperochloa kingii Pinus ponderosa/Festuca arizonica Populus tremuloides/Carex geyeri Populus tremuloides/Festuca thurberi
4. MOIST SHRUB ASSOCIATIONS Subalpine
Abies lasiocarpa-Picea englemannii/ Vaccinium myrtillus Abies lasiocarpa-Picea englemannii/ RIBE
Abies lasiocarpa-Picea englemannii/ Erigeron eximius
Abies lasiocarpa-Picea englemannii/ Pachistima myrsinites Abies lasiocarpa-Picea englemannii/ Rubus parviflorus
Abies lasiocarpa-Picea englemannii/ Vaccinium scoparium Pinus contorta/Shepherdia canadensis Pinus contorta/Vaccinium myrtillus Pinus contorta/Vaccinium scoparium Pinus contorta/Juniperus ccrmunis Picea englemanni/Vaccinium scoparium
Montane
Pseudotsuga menziesii/Jamesia americana Pseudotsuga menziesii/
Subalpine fir/elk sedge Subalpine fir-Englemann spruce/ elk sedge
Lodgepole pine/elk sedge
Blue spruce/grass Blue spruce-Douglas fir/ foenea sedge
Blue spruce-Douglas fir/ Arizona fescue Douglas fir/ross sedge Douglas fir/elk sedge White fir-Douglas fir/ Arizona fescue White fir-Douglas fir/ sparse
Ponderosa pine/sun sedge Ponderosa pine/blue gramma Ponderosa pine/elk sedge Ponderosa pine/spike fescue Ponderosa pine/Arizona fescue Aspen/elk sedge Aspen/Thurber fescue
Subalpine fir-englemann spruce/ Rocky Mountain whortleberry Subalpine fir-englemann spruce/ Ribes ssp.
Subalpine fir-englemann spruce/ fleabane
Subalpine fir-englemann spruce/ myrtle pachistima Subalpine fir-englemann spruce/ thimbleberry
Subalpine fir-englemann spruce/ whortleberry
Lodgepole pine/buffaloberry Lodgepole pine/Ry. Mt. whortelberry Lodgepole pine/whortleberry Lodgepole pine/cortmon juniper Englemann spruce/whortleberry
Douglas fir/jamesia Douglas fir/


Pachistima myrsinites Pseudotsuga menziesii/
Physocarpus monogynus Pseudotsuga menziesii/Acer glabrum Pseudotsuga menziesii/
Arctostaphylos patula Pseudotsuga menziesii/Quercus gambelii Picea pungens-Pseudotsuga menziesii/ Arctostaphylos uva-ursi Abies concolor-Pseudotsuga menziesii/ Arctostaphylos uva-ursi Abies concolor-Pseudotsuga menziesii/ Erigeron eximius
Abies concolor-Pseudotsuga menziesii/ Acer glabrum
Abies concolor-Pseudotsuga menziesii/ Quercus gambelii
Abies concolor-Pseudotsuga menziesii/ Vaccinium scoparium Pinus ponderosa/Arctostaphylos patula Pinus ponderosa/Juniperus camtunis Pinus ponderosa/
Arctostaphylos uva-ursi Populus tremuloides/
Symphoricarpos oreophilus Pcpulus tremuloides/
Amelanchier alnifolia-Prunus virginiana Populus angustifolia/
Amelanchier alnifolia
myrtle pachistima Douglas fir/
mountain ninebark Douglas fir/Ry. Mt. maple Douglas fir/ bearberry
Douglas fir/gambel oak Blue spruce-Douglas fir/ kinnikinnick White fir-Douglas fir/ kinnikinnick White fir-Douglas fir/ fleabane
White fir-Douglas fir/
Rocky Mountain maple White fire-Douglas fir/ gambel oak
White fir-Douglas fir/ whortleberry Ponderosa pine/bearberry Ponderosa pine/common juniper Ponderosa pine/ kinnikinnick Aspen/
mountain sncwberry Aspen/
serviceberry-chokeberry
Narrcwleaf Cottonwood/ serviceberry
UNSUITABLE LOCATIONS - FORB UNDERSTORY ASSOCIATIONS OR WET ASSOCIATIONS
Subalpine Pinus flexilis/
Trifolium dasyphyllum Pinus aristata/
Trifolium dasyphyllum Picea englemannii/
Trifolium dasyphyllum Picea englemannii/Equisetum arvense Picea englemannii/moss Abies lasiocarpa-Picea englemannii/ moss
Abies lasiocarpa-Picea englemannii/ Linnaea borealis
Abies lasiocarpa-Picea englemannii/ Calamagrostis canadensis Abies lasiocarpa-Picea englemannii/ Salix glauca
Abies lasiocarpa-Picea englemannii/ Senecio triangularis
Limber pine/
whiproot clover Bristlecone pine/ whiproot clover Englemann spruce/ whiproot clover
Englemann spruce/field horsetail Englemann spruce/moss Subalpine fir-englemann spruce/ moss
Subalpine fir-englemann spruce/ twinflower
Subalpine fir-englemann spruce/ bluejoint reedgrass Subalpine fir-englemann spruce/ grayleaf willow
Subalpine fir-englemann spruce/ arrcwleaf groundsel


Montane
Populus tremuloides/
Lathyrus leucanthus Populus tremuloides/
Thalictrum fendleri Populus tremuloides/
Calamagrostis rubescens Populus tremuloides/
Ligusticum ssp.
Populus tremuloides/
Pteridium aquilinium Picea pungens/
Amelanchier alnifolia-Sweida sericea
Pinus ponderosa/Quercus gambelii Populus angustifolia-Picea englemannii Amelanchier alnifolia Populus angustifolia-Picea englemannii Lonicera involucrata Populus angustifolia-Picea englemannii Salix exigua-Betula fontinalis Populus sargentii/
Symphoricarpos occidentalis-Elymus cinereus
Aspen/
aspen peavine Aspen/
meadcw-rue
Aspen/
pinegrass
Aspen/
ligusticum species Aspen/
bracken fern Blue spruce/
serviceberry-dogwood
Ponderosa pine/gambel oak Cottonwood-Englemann spruce/ serviceberry
Cottonwood-Englemann spruce/
Cottonwood-Englemann spruce/ coyote willow-river birch Plains cottonwood/
sncwberry-gian wild rye


Appendix IV - Scale of Trail location Suitability
Most Suitable
1. 0% - 3% trails on summits, toeslopes, and valley bottoms with dry qramminoid plant associations
2. 0% - 3% trails on summits, toeslopes, and valley bottoms with dry shrub plant associations
3. 3% - 6% trails on shoulders and foots lopes with dry graiunlnoid plant associations
4. 3% - 6% trails on shoulders and foot slopes with dry shrub plant associations
5. 0% - 3% trails on summits, toeslopes, and valley bottoms with moist qramminoid plant associations
6. 0% - 3% trails on summits, toeslopes, and valley bottoms with moist shrub plant associations
7. 3% - 6% trails on shoulders and footslopes with moist qramminoid plant associations
8. 3% - 6% trails on shoulders and footslopes with moist shrub plant associations
9. 6% - 9% trails on backslopes with dry qramminoid plant associations
10. 6% - 9% trails on backs lopes with dry shrub qramminoid plant associations
11. 6% - 9% trails on backs lopes with moist qramminoid plant associations
12. 6% - 9% trails on backs lopes with moist shrub plant associations
Least Suitable
Field Descriptions of Scale locations SUITABLE LOCATIONS
1. & 2. Nearly level, dry meadows or open forests with qramminoid or shrub understories
Areas most suitable tor trail location are nearly level and dry. locations are typically on exposed ridges or mesa summits, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. These are areas of lew snow accumulation or where snow blcws off early in the spring. The soils


here are very well drained with a relatively low moisture content. They tend to range frcm rocky or gravelly soils to coarse loams. To minimize erosion, trails located in these areas should not exceed 3%.
3. & 4. Gently sloping, dry meadows or open forests with qramminoid or shrub understories
The second most suitable areas for trail location have very gentle slopes and are dry. Locations are typically on exposed ridge and mesa summits or shoulders, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. These are areas of lew snow accumulation or where snow blows oft early in the spring. The soils here are very well drained with a relatively low moisture content. They tend to range from rocky or gravelly soils to coarse loams. To minimize erosion, trails located in these areas should not exceed 6%.
5. & 6. Nearly level, moist meadews or forests with granminoid or shrub understories
The third most suitable locations tor trails are nearly level and relatively moist. These may be protected ridge suntrnts, toeslopes or valley bottoms. Typical locations my be streamsides, lake margins, draws, benches, or meadews. Also included are areas protected frcm extreme sun or wind. Aspect may be northerly to easterly, especially where little snow accumulates; or southerly to southwesterly where snow tends to accumulate. Soils are well drained and tend to range frcm gravelly and sandy loams to sandy clays. To minimize erosion in these areas, trail slopes should not exceed 3%.


7. & 8. Gently sloping, moist meadows or forests with gramminoid or shrub
understories
The fourth most suitable trail locations for trails are gently sloping and relatively moist. These may be protected ridge summits or shoulders, or footslopes. Typical locations may be streamsides, draws, benches, or meadcws. Also included are areas protected from extreme sun or wind. Aspect may be northerly to easterly, expecially where little snow accumulates, or southerly to southwesterly where snow tends to accumulate. Soils are well drained and tend to range from gravelly and sandy loams to sandy clays. To minimize erosion in these areas, trail slopes should not exceed 6%.
9. & 10. Sloping, dry meadows or open forests with qrairminoid or shrub understories.
The fifth best locations tor trails are moderately sloping and dry. These are backslcpes and draws. Typical locations may be exposed or windswept slopes and may tend to have a southerly to westerly aspect. These are areas of lew snow accumulation or where snow blows off early in the spring. The soils here are very well drained with a relatively lew moisture content. They tend to range from rocky or gravelly to coarse loams. To minimize erosion, trails located in these areas should not exceed 12%.
11. & 12. Sloping, moist meadcws or open forests with qrairminoid or shrub understories
The sixth most suitable locations for trails are moderately sloping and moist. These are backslcpes and draws. Typical loactions may be northerly or easterly


slopes and draws where little snow accumulates, or southerly to westerly slopes and draws where sncw tends to accumulate. These are areas protected from extreme wind descication. Soils are well drained and tend to range fran rocky and coarse loams to finer loams. To minimize erosion, trails located in these areas should not exceed 12%.
UNSUITABLE LOCATIONS FOR TRAILS
A. Steep trail grades and extended slope lengths
Steep slopes or terrain which requires trail slopes to exceed 12% for prolonged stretches are unsuitable due to excessive soil erosion. Erosion increases with both grade and slope length. On trails of 12% slope and steeper, maintained for 100', erosion increases dramatically. Trails may be located on slopes which are greater than 12%, but the slope of the trail should not exceed 12%.
B. Wet sites
Wet sites are unsuitable due to the extremely low resistance of the soil and vegetation to trampling. Trampling on a saturated soil compacts it and destroys its structure. This diminishes the soil's resistance to erosion as well as decreases ease of root penetration. In addition, plants growing in saturated conditions tend to have a high water content in their tissues, and thus are very likely to be broken upon trampling.


C. Forb-daninated understories
Forb understories are unsuitable due to the low trampling resistance of the vegetative form of many torbs. Many forbs have single steins with leaves arising This form has been noted to be the least resistant to trampling.
fran the stem.


BIBLIOGRAPHY
Hendee, John C.; Stankey, George H.; Lucas, Robert C.. Wilderness Management. U.S.D.A. Forest Service, Pub. No. 1365; 1978.
A basic text, the "bible", on history, managment phioosophy, and issues relating both to the land and the user.
Heimichs, J.; "Wilderness - Can We Have It and Use It Too?"; Amer. For.: 16-53; 1980.
Range of impacts and management challenges in wild lands.
Cole, D. N.; "Assessing and Monitoring Backcountry Trail Conditions"; Res. Pap. INT-303. Ogden, UT: U.S.D.A. Forest Service, Intermountain Forest and Range Experiment Station; 1983.
Approaches to measuring trail conditions, as applied to the Selway-Bitterroot Wilderness in Montana.
Weintraub, A.; Adams, R.; Yellin, L.; "Land Management Planning: A Method of Evaluating Alternatives". Res. Pap. PSW-167. Berkeley, CA: U.S.D.A. Forest Service, Pacific Southwest Forest and Range Experiment Station, 1982.
Alternatives in use distribution among campsites
Liddle, M. J.; "A Selective Review of the Ecological Effects of Human Trampling on Natural Ecosystems"; Biol. Conserv. (7): 17-33; 1975.
British. Impacts of trampling, and management actions to treat impacts.
Dale, D.; Wever, T.; "Trampling Effects on Vegetation of the Trail Corridor of Northern Rocky Mountain Forests". Ecology (?).
Impacts to trails, species composition, and frequency of species.
Cole, D.N.; "Estimating the Susceptibility of Wildland Vegetation to Trailside Alteration"; J. App. Ecol., vol. 15; 1978.
Changes in species composition, cover, and resistance to trampling along trails in Eagle Cap Wilderness.
Cole, D. N.; and B. Ranz; "Temporary Campsite Closeure in the Selway-Bitterroot Wilderness", J. For., vol. 81; 1983.


Reasons for closure of lakeside campsites and resultant shifts in use patterns.
9. Cole, D. N.; and R. K. Fichter; "Campsite Impact on Three Western Wilderness Areas"; Environ. Man., vol. 7, no. 3; 1983.
Relationship between frequency of use and amount of impact on campsites in Montana and Oregon.
10. Cole, D. N.; and J. Benedict; "Wilderness Campsite Selection - What Should Users Be Told?"; Park Science 3(4): 5-1; 1983.
Impacts, conditions of campsites and visitor education. Standard classification of campsite condition and recommended frequency of use.
11. Clark, R. N.; and K. B. Downing; "Why Here and Not There: Conditioning Nature of Recreation Choice", In: Proceedings - Symposium on Recreation Choice Behavior; Missoula, MT, 3/22-23/84.
Factors relating to users' decision-making for selection of recreation area.
12. Lucas, R.; Wilderness Management Research Project Leader, U.S.F.S., Intermountain Forest and Range Experiment Station, Missoula, MT; phone conversation, Oct. 9, 1985.
Discussion on my thesis approach and relevant research. He co-authored the "bible" - see 1. He liked my approach and didn't knew of a similar research effort.
13. Vallejos, R.; Assistant Recreation Forester, U.S.F.S., Mount Evans Wilderness Area, CO; phone conversation, Oct. 21, 1985.
Discussion of history of existing trail locations, user demographics, relationship of adjacent roads to access.
14. Clawson, M.; and B. Held; The Federal Lands - Their Use and Management; Johns Hopkins Press, Baltimore, MD; 1957.
Managment history of federal lands.
15. Brubaker, S.; ed. Rethinking the Federal Lands; Johns Hopkins Press, Wash, D.C.; 1984.
History of management policies of federal agencies.


16. Caldwell, L. K.; "An Ecosystems Approach to Public Land Policy"; In; Western Resources Conference, 10th, Colo. State Univ.; 1968.
Philosophy concerning need to modify existing, historic approach of viewing land development and management toward wholistic, ecological approach.
17. Robinson, G. 0.; The Forest Service, A Study in Public Land Management; Johns Hopkins Pres, Baltimore, MD; 1975.
Management proceedures and policies of the Forest Service, sustained-yield/multiple use concept.
19. Schechter, M.; and R. C. Lucas; "Simulation of Recreational Use for Park and Wilderness Management"; Johns Hopkins Press, Baltimore, MD; 1978.
Discussion on the use and validity of a computer simulator for assessing user encounters, and different management options, on trails.
20. Brockman, C. F.; and L. C. Merriam, Jr.; Recreational Use of Wild Lands; McGraw-Hill; 1979.
Management philosophy and objectives for recreation on undeveloped lands.
21. Lucas, R. C.; "Visitor Characteristics, Attitudes, and Use Patterns in the Bob Marshall Wilderness Complex, 1970-82."; U.S.D.A. Forest Service, Intermountain Research Station, Ogden, UT; 1985.
Relationships of camping practices, party size, and impact by hikers, horse packers, and outfitters.
22. Cole, D. N.; "Campsite Conditions in the Bob Marshall Wilderness, Montana"; U.S.D.A. Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT; 1983.
Relationship of site moisture and vegetation form to campsite conditions.
23. Daubenmire, R. F.; Plants and Environment, a Textbook of Autecology; John Wiley and Sons, Inc., New York, NY; 1974.
How habitat factors affect individual plants.
24. Daubenmire, R. F.; Plant Conmunities, A Textbook of Plant Synecology; Harper and Row, New York, NY; 1968.
How plants relate to each other and function in communities.


25. Johnston, B. C.; Plant Associations (Habitat Types) of Region Two; U.S.D.A. Forest Service, Rocky Mountain Region; Lakewood, CO, 1984.
Description of plant associations found in Colorado, New Mexico, Wyoming, Kansas, and Nebraska.
26. Johnston, B. C.? Key to the Forested Plant Associations of Northern
Colorado and Southern Wyoming; U.S.D.A. Forest Service, Rocky Mountain Region; Lakewood, CO; 1985. •
Key to identifying and summary of site conditions of forests of that area.
27. Brady, N. C.; The Nature and Property of Soils; MacMillan Publishing Co., Inc., New York, NY; 1974.
Textbook of soil properties.
28. Baver, L. D.; W. H. Gardner; W. R. Gardner; Soil Physics; John Wiley and Sons, Inc., New York, NY; 1972.
Textbook of physical properties of soils in engineering and agricultural applications.
29. Barbour, M. G.; J. H. Burk; W. D. Pitts; Terrestrial Plant Ecology; Benjamin Cummings Publishing Co., Inc.; 1980.
Textbook of plant ecology.
30. Cronquist, A.; A. H. Holmgren; N. H. Holmgren; J. L. Reveal; R. K.
Holmgren; Intermountain Flora, Vascular Plants of the Intermountain _____West; Columbia University Press, New York, NY; 1977.
Key of vascular plants of the Intermountain West.
31. Willard, B. E.; J. Marr; "Effects of Human Trampling on Tundra in Rocky Mountain National Park"; Biol. Conserv.; 1970.
Susceptibility of various tundra ccmrnunities to trampling damage.
32. Harrington, _; Plants of Colorado Key of all plants found in Colorado.
33. Cole, D. N.; and E. G. S. Schreiner, compilers; "Impacts of Backcountry Recreation: Site Management and Rehabilitation - An Annotated Bibliography"; U.S.D.A. Forest Service General Technical Report INT-121; Intermountain Forest and Range Experiment Station, Ogden, UT; 1981.


Collection of summaries of research.
34. Dunne, T.; and L. B. Leopold; Water in Environmental Planning; W. H. Freeman and Company, San Francisco; 1978.
The role of water in environmental planning.
35. Hooper, Lennon; NPS Trail Management Handbook; U.S.D.I., National Park Service, Denver Service Center.
Guide to locate and build trails.
36. U.S.F.S.; Trails Management Handbook; U.S.D.A. Forest Service.
Guide to locate and build trails.
37. Proudman, Bobert D.; AMC Field Guide to Trail Building and Maintenance; Applachian Mountain Club; 1981.
Guide to locate and build trails.
38. Ruhe, Robert; Gecmorphology; Houghton Mifflin Co.; Boston; 1975.
Geology and landform.
39. U.S.F.S.; Recreation Opportunity Spectrum; U.S.D.A. Forest Service.
Discussion of appropriate development levels and types of use of trails in various settings.
40. U.S.F.S.; Land and Resource Management Plan, Shoshone National Forest; U.S.D.A. Forest Service, Cody, WY; 1985.
Management objectives, directions and standards.
41. Carr, Lee; Wilderness Recreation Forester; U.S.F.S., Rocky Mountain
Regional Office, Lakewood, CO; numerous personal conversations, Oct. -Apr., 1986.
Numerous conversations concerning wilderness trails and this thesis.
42. Trenholme, Richard; Soils Specialist, Intermountain Soils; Denver, CO; phone conversations, March - April, 1986.
h


Discussions on Colorado gecmorphology and soils.
Soil Conservation Service; National Soils Handbook; U.S.D.A. S.C.S. May 1983.
Proceedures for performing surveys and tests on soils.


Full Text

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GUIDELINES FOR MINIMUM IMPAcr TRAIL lOCATION In Colorado Conifer Forests Prepared in Partial Fullment for Ma.ster of Landscape Architecture Degree. University of Colorado at Denver College of Design and Planning By Ma.ry Lou McCandless Due THIS BOOK CONTAINS 20 SLIDES IN POCKET OF INSIDE BACK COVER. -r-\ _ ____, .. , ... I ----!---f \ _ .. --I \L____ ... __.,.,

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Thesis Committee Signatures

PAGE 3

TABLE OF CCNI'ENl'S PART I: THESIS RESEARCH SECT!ON I The Scope of This Thesis ••••••....•••••••••••.•••••••.•.•••. 1 SEX::TION II Wilderness Trail Conditions Tbday ••••••••••••••••••••••••••• 4 SECT!ON III Sl.mlr\ary of Ila. ta . . . . . . . . • • . • . . . • . • • . • . . . . . . . . . . . . . • . . . . . . . . . . . 6 SECT!ON N Guidelines for Locating Minimal Impact Trails ••••••••••••••• 10 SECT!ON V OVerview of Relevant landscape Olaracteristics • • • • • • • • • • • • • 21 SEX::TION VI Finding OVerall Trampling Resistance and Trail Location Suitability -The Author's Research Process • • • • • • • • • • • • • • • • 29 P.AR'I' I I : CASE S'll.JDY • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 4 8 APPENDIX I Wilderness Act of 1964 ................................... 58 APPENDIX II Wilderness Use •••••••••••••••••••.••.•••••••••.•.••.••••.. 63 APPENDIX III Colorado Conifer Forest Plant Associations: Resistance to Trampling • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 64 APPENDIX N Scale of Trail Location Suitability ••••••••••••••••••••••• 68 BIBU.c::x::iRAPIIY' • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 7 3

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I 'lbe of 'lhi.s 'lbesis OUr wilderness areas are being loved to death. Trail and carrpsi te conditions have been declining in recent years due to increased use. Research shc:Ms, hc:Mever, that frequency of use is not the sole factor in trail and carrpsi te degradation. ( 8, 9 ) Perhaps more irrcportant are landscape characteristics and user practices. ( 8, 9) .t-t:>st trails in wilderness today are remnants of old fire-fighting or stock-driving trails. (13, 41) They tend to follow streams uphill and end, perhaps at a lake. Or they cross over a saddle and dCMn another draw. These streamside locations are often soggy, and hard to maintain. (13) The assumption of this thesis is that same trails in wilderness areas are not located in areas most resistant to trampling. The thesis hypothesis is that relative resistance to trampling impacts can be determined, and that trail location guidelines can be drawn on the basis of that resistance. The guidelines which result will then be tested in a case study. For the purpose of this thesis only, the location of the Contenental Divide National Scenic Trail will be determined as it nms through Huston Park Wilderness Area, Medicine Bc:M National Forest, Wyaning. Trail location guidelines generated by this thesis will be usable by anyone designing a trail in Colorado coniferous forests. The guidelines are intended to be used in conjunction with mapped plant associations and soils for each specific project. However, the basic principle of trampling resistance as determined by this thesis, should still enable satisfactory trail location without extensive resource mapping. The scope of this thesis has been to determine which physical properties of soils and vegetation contribute to 1

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resistance to trampling; and in turn, to identify how those properties manifest into a physical fonn which can be readily mapped and identified in the field. The physical properties of soils, in part, detennine erosion of the trail surface. Physical properties of vegetation detennine denudation of the trail margins. Although in the guidelines same consideration has been given to hiker experience, this thesis is primarily concerned with land resources and their resistance to trampling as a basis for locating trails. The element of user preference to trail location was anitted fran the evaluation process due to limitation on time and project scope. Knowledge of user preference is certainly of equal importance as land resistance in detennining trail location, and together user and land factors would detennine the final roost workable locations. Research on user preference to trail location is clearly needed. The value of this thesis' results range beyond trail location. The principles of land resistance to trampling can be awlied to other fonns of outdoor recreation and to other uses on native soil and vegetation conditions. In addition, the IOOdel for trampling resistance is a tool which could be applied to other areas of the country by inserting local native vegetation into the IOOdel for plant associations. Trail location guidelines for minimal trampling i.npact are clearly needed. No such guidelines exist to the author's knowledge. No other guidelines address the importance of vegetation as it relates to trail margins. other guidelines address trail grade, but fran a user's standpoint rather than that of soil erosion. {35, 36, 37) 2

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CXle of the rna jor builder of trails in the west is the U.S. Forest Service. '!hat process of trail location begins with the agency's planning process, condsidering objectives set for each Forest in that Forest's Land Management Plan. ( 40) 'Ibe process then considers the predetennined level of trail develcprent and use, according to the Recreation Opportunity Spectrum System. (39) Many forest managerrent and administrative factors are addressed before the trail corridor is located. ( 36, 40, 39) '!be general trail corridor is located by looking at aerial photos and topographic maps, then the trail centerline is staked in the field. (35) Standards for trail grade and length are set, but relate to trail difficulty and not to resource protection. (35) No mention is made to minimize soil erosion, or encourage use in Irore resistant vegetation types. As increased recreational use intensifies impacts on wilderness land, the need arises to relocate stretches of problem trails. Due to lack of funding, trails in wilderness receive very little maintenance. 'Iberefore, all trails should be in the JOOst optimum locations -where i.npact fran trampling is minimal. The guidelines produced by this thesis would be particularly useful for relocation of problem wilderness trails. HCMever, these guidelines are useful for location of trails anywhere in a Colorado coniferous forest. 3

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II Wilderness Trail Cclldi.tioos Today All designated wilderness areas are a result of the Wilderness Act of 1964. (See Appendix I). It established the National Wilderness Preservation System to inclooe tracts of wild land so that "settlerrent does not occupy and rocx:lify" all lands within the United States. Wilderness is defined in the Act as "land untramneled by man, man is a visitor who does not remain". It is further defined as undeveloped federal land which 1.) appears primarily natural and unmodified by man, 2.) has outstanding opportunities for solitude or primitive and unconfined type of recreation, 3.) has at least 5, 000 acres, and 4. ) may also contain ecological, geological, or other features of scientific, educational, scenic, or historical value. '!he Act mandates that designated wildernesses be preserved in their natural state for use and enjoym:mt by present and future generations. Thus, wilderness areas must be managed to protect the existing natural resources, yet at the same time allow wildernessdependent types of recreation. A parcel of land characterized as primitive can only becane designated as a wilderness area by presidential proclamation or an act of Congress. In the lower forty eight states, there are 439 wilderness areas covering 86 million acres, (41) and nl..m'erous m:::>re proposed areas before Congress awaiting decision. (See Appendix II). '!he Forest Service, National Park Service, Bureau of Land Managerrent, and Fish and Wildlife Service are the federal agencies managing the existing and proposed wilderness areas. '!here is a substantial and increasing body of research concerning recreational use in wilderness much of it originating at the University of z.t::>ntana and the 4

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Forest Service Range and Experiment Station in that region. 'Ihat research identifies several major impacts of recreational use, all related to trampling. (3, 6, 7, 8, 9, 22, 33) The primary impact to trails is soil erosion, which deepens the trail tread. (3, 5, 6, 7, 33) Same stretches of trails studied in Montana were three feet (3) I>ss of vegetative cover on trail margins widens the trail tread. ( 3, 5, 6, 7, 33 ) This loss of cover results in exposure of bare mineral soil, which is then subject to erosion and canpaction. (28) Also noted is a change in species composition along trail margins, occurring in roughly three-foot wide bands on either side of the trail. (3, 6, 7) This change in compositon is due to invasion of species into the disturbed margins. Impacts to campsites are much the same as to trails. Deterioration of campsites very quick! y, and revegetation is slCM. Extreme loss of vegetative cover -74% -typically occurs with only light use, one or two nights a year. (8, 9) After the initial deterioration, increased use is unlikely to cause a great deal rrore damage. ( 8, 9) Thus, limi. ting use is not the total answer to the problem. The conditions of trails and campsites are more a function of user practices and inherent site characteristics. The identification of site characteristics rrost resistant to impacts is the direction of this thesis. 5

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SEX:'l'ICfi III Samnary of the 18ta The key to most suitable trail locations lies in determining landscape types which are most resistant to the effects of trampling. This involves analysis of the trail surface itself -of the soils and trail grades, as well as the trail margins -or the surrounding vegetation. Tb determine resistance of the trail surface, the effect of different trail grades on soil textures was analyzed. 'Ihe Universal Soil IDss Equation was used to calculate erosion rates on various trail scenarios. Trail grades selected for use with the equation were: 3%, 6%, 9%, 12%, 15%, 20%, and 30%. 'Ihe resultant erosion rates were plotted on a graph to identify trends related to trail grades. 'Ihree trends emerged: 1) on trails of 6% and less, the texture of soil was not a significant factor in the rate of erosion. Trail grade was the most irrportant factor influencing erosion; 2) on trail grades between 9% and 15%, soil texture was more irrportant than grade. 'Ibis is especially true between 12% and 15%. Coarser-textured soils on these grades are significantly less erodable than finer-textured soils. 3) on grades above 15%, all textures are highly erodable. Tb determine the resistance of trail margins, the canbinations of vegetative fonn and moisture of different plant ccmnunities was analyzed. Vegetative fonns and moisture detennine a plant's overall resistance to being killed by trampling. Vegetative fonn also detennines a plant' s ability to spread vegetatively into denuded trail margins. The different vegetative fonns of forest understory plants were analyzed for trail margin suitability. They were granminoids, shrubs, arx1 forbs. Granminoids are grass-like plants. Shrubs 7

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are multiple-stemred plants with sane anount of woody grc:Mth. Forbs are all herbacious plants which are not granminoids, lichens, or roosses. 'Ihese vegetative fonns were analyzed in dry, rooist, and wet scenarios. 'Ihe results of that analysis produced a ranking of vegetative resistance to trampling. It sl'lovled that dry granminoid ccmnuni ties are the roost resistant to trampling, follc:Med by dry shrubs, rooist granminoids, and finally rooist shrubs. Forb and all wet oammunities have very poor resistance to trampling and are unsuitable for trail margins. '!his ranking of vegetative resistance becare a roodel of suitability for trail margins. 'Ihe roodel can be used to determine suitability of native plant associations for trail margins. 'Ihe roodel is used by inserting a particular plant association into its apprcpriate category in the roodel. For example, the plant association subalpine fir-Englernann spruce/ross sedge grc:Ms in very well-drained areas, having a dry rooisture regime. Ross sedge, the understory species, is a granminoid. 'Iherefore, subalpine fir-Englernann spruce/ross sedge is a dry granminoid plant association. 'Ihe roodel indicates that all dry granminoid plant associations have a high suitability for trail margins. 'Ihe roodel can be used in this manner to identify trail margin suitability of any plant association of any region. 'Ihe roodel is applicable to any region because it is based on universal factors which contribute to trampling resistance. The different trail grades that were used in calculations of soil erosion where matched to appropriate hillslope positions where that grade of trail would roost likely be found. 8

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The different cambinations of hillslope position and trail grade, with suitable vegetation forms were ranked for overall suitability for trail location. This formed a scale of location suitability. The most suitable location for trails is: 0% -3% trails on surrmi.ts, toeslopes, and valley bottans with dry grarrmi.noid plant cammunities. The least suitable trail location is: 6% -9% trails on backslopes with moist shrub plant oammunities. Unsuitable locations for trails are on: steep trail grades, wet plant sites, and forb daninated understory cammuni ties. Finally, guidelines for minimum impact trail location were developed. The guidelines are a process to aid the trail designer in locating the most sui table trail corridors fran within an entire project site. They are a planning tool to be used in the first stage of trail design on the drawing board. The guidelines are the result of a long analysis done by the author to help her identify landscape characteristics which contribute to tranpling resistance. The professional should apply only the guidelines to locate resistant trail corridors. The analysis process does not need to duplicated each time the prof essional wishes to locate trail corridors. Final trail centerlines can only be dete:rmined in the field, considering all surface conditions. The Scx:JPe of this trail suitability analysis was limited to the factors of soil resistance to water erosion and vegetative resistance to trampling. other factors were anitted due to the limitation on time. Factors excluded fran consideration were soil resistance to wind erosion, the effects of hiking shoes and horses on soil erosion, and the analysis of user preferences. 9

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SOC'l'ICE IV Gri.delines for IDeating Trails of Minimal 'J.'ralrt>ling !Dpict The following guidelines are a process for locating trail corridors based on resistance to trampling. Trail locations resulting fran these guidelines will result in minimal irrpact to trampling. These guidelines are intended for use by the landscape archi teet in the initial phase of a trail design project. The process outlined is a planning tool to aid him in locating the nost sui table trail corridors fran within the entire project site. The professional must hav e access to reliable resource maps to be able to use this process. He must have: 1) vegetation mapped showing daninant species of the forest understory, 2) a soil survey showing textural classes of the top 4" 6" of soil, such as an SCS soil survey, 3) a topographic map showing all surface landmark features such as streams, lakes, falls, mines, glaciers, townsites, trails, and roads. These maps must all be at the same scale. The larger the scale of the maps, the greater the anount of detail will be shown. large scale maps are preferable to small scale maps. However, often the professional will only be able to obtain the necessary information at a scale of 1:24000. Working at that scale it is necessary to understand that the narrowest trail corridor located will be roughly 40 50 feet wide. The planning process outlined in these guidelines will enable the professional to locate the nost suitable trail corridors on the project site as a necessary first step in final trail location. It is manditory to realize that final trail centerlines can only be determined on the ground, considering all surface corrli tions •• 10

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DFSIGN OUTERIA '!here are four major factors necessary to consider for locating trails that are resistant to trampling. '!hey are: vegetation types that are resistant to trampling; the canbination of soil textures and trail grades that are resistant to water erosion; relative hills lope positions; and destination and access points of the site. Vegetation '!he vegetation that surrounds a trail is important because it can prevent the trail fran becaning excessively wide. Trails should be located on vegetation that is resistant to being killed by trampling. 'Ibis initial resistance helps prevent the trail margins fran expanding. Also irrportant is the ability of the surrounding vegetation to spread back into denuded patches of the trail margins. An anlaysis of factors contributing to vegetation suitability for trail margins appears in the data section of this thesis. '!he results of that analysis produced the following ranking of vegetation types. High Suitability -1. dry granrninoid CClllltlli1ities 2. dry shrub ccmnuni ties 3. IOC>ist granrninoid carrm.uri ties Fair Suitability -4. IIDist shrub ccmnunities Unsuitable wet or forb oarnmunities Trails should not be routed through areas with understories daninated by forbs or boggy areas with wet vegetation. 'lhese types of vegetation have poor resistance to trampling. 11

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Soils The soils and grades of a trail are important because together they determine how eroded and deep a trail can get. Trails located on highly erosive, finer-textured soils should have gentle grades to minimize the effects of water erosion. Fine textured soils are constraints to steep trail grades. Coarser textured soils are more resistant to water erosion than fine textured soils, and can tolerate steeper trail grades. These coarser textured soils and stable rock are CHX>rtuni ties for steeper trail grades. Keep trail grades to the following limits. Hillslope Position Soil Texture fine loams silts clays rocky soil coarse loams stable rock Trail Grade 0% -6% 0% -15% 0% + Identifying the relative positions, or parts, of a hillslope can help the trail designer in two ways. Firstly, having the positions delineated helps the designer to understand a site's tq>ography and landform at a quick glance. This can help the designer to provide a better variety of trail location to heighten the user's experience. Secondly, the delineation of hillslope positions can give the designer a quick idea of probable trail grades at different places on the hill. 1 2

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The positions on a hillslope are: sunmit: flattest part of the top of the hill shoulder: transition between sunmi t and backs lope; where the gradient o the hill starts to increase backslope: steepest part of the hill footslope: transition between backslope and toeslope; where the gradient of the hill starts to decrease. toes lope: bottan of the hill; transition between foots lope and valley valley: flattest land between 2 hills. Trails of certain grades are rrore likely to occur on particular positions of a hillslope. They are: sunmit and shoulder: 0% 6% backslope: 0% + footslope, toeslope, valley: 0% 6% Destination and Access Points Destination points and access points are the focal points of a trail system. It is important that a trail is located where hikers will use it. otherwise, the hiker will create his own path to get to his destination, and others will follow his lead. Soon a new path appears. To avoid unplanned trails, an adequate circulation pattern must be provided which encompasses a variety of probable destination points over the entire site. In addidi ton, access points to the

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internal circulation pattern must be sufficiently spaced to avoid overuse and underuse of any one area. Possible Destination Points: lakes, falls, glaciers, mines, ghost to.ms, existing trails, etc. Access Points: existing trails, roads, campgrounds picnic areas, etc. 'lbe process of locating rni.nima.l inJ?act trails has two parts: the mapping stage and the planning stage. MAPPING S'mGE 1. Map the vegetation types. Group together and map as a single unit all dry granminoids. label these as 1' s. Do the same for dry shrubs, m:>ist granminoids, and m:>ist shrubs. Group together wet and forb plant associations. 'lbese will be constraints to trail location. label the units as such: dry gramminoids -1 dry shrubs 2 moist gramminoids -3 m:>ist shrubs 4 wet and forbs -U 14

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This is a ranking system which indicates trampling resistance at a quick glance. Appendix III can be used to identify which category a plant is in. 2. Map the highly erodable soils. Notice all rock areas, or rocky soil, cobbly, gravelly, or sandy loams. These will provide the most flexibility for trail grades. Map all other soil textures as 1 unit and label it as a highly erodable soil. These soils will be constraints to trail grades. 3. Map the hillslope positions. Indicate as single units: 1) sunmi ts and shoulders 2) backslq;>es 3) foots lopes, toeslq;>eS, and valleys The point at which the slq;>e of the hill starts to steepen will be the lower edge of the sunmit/shoulder unit. Similarly, the point at which the slope of the hill starts to flatten out will be the lower edge of the backslq;>e unit. All gently graded bottanland will be a valley unit. 4. Map the probable destination points and access points. PlANNING STAGE 5. Create an internal circulation pattern. Route possible trail corridors through sui table plant associations, linking destination points together. Route the corridors through a variety of different plant associations if possible. 1 5

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Avoid using lakes with boggy areas nearby as destination points. Fran each major access point on the border, route an access trail to the internal circulation system. Route the different access trails to join the internal system at widely separated junctions. Avoid creating circulation patterns which encourage overuse at one destination point and underuse at another. If there is only one probable destination point in the site, create a loop out of the access trail. A loc.p trail is Irore interesting than a trail that has to be completely backtracked. 6. Use a variety of trail grades and hills lope positions if possible. Variety can be added to a trail be routing it over different positions of a hill. For exanple, the trail may follow a valley for a while, then climb over a ridge and down to another valley. '!his n:rust be done artfully to avoid seeming contrived. 7. Oleck that the trail grades are appropriate with the underlying soil texture. On the finer soils keep trail grades under 6%. Trail grades of 9% ' 15% should only occur on coarser soils. Trail grades over 15% should only occur on very rocky soil or stable rock. Make any trail grade adjustments as necessary to accx:::moodate soil texture. 16

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8. locate final centerlines in the field, making any necessary adjustments for site conditions. Additional considerations to final trail location -based on preference of resistance in vegetative fonn, soil texture, and m::>isture: 1. In a choice between gramninoid or shrub daninated understories, remember that gramninoids are m::>re resistant to 2. Rather than taking a trail through the center of a meadow, route it along one edge, preferably the north or east edge, as it may be drier there. '!he trail, or it's users, are less conspicuous there. In addition, the interface of a meadow and forest can be a m::>re exciting position than the middle of a meadow because it relates to both meadow and forest. 3. Follow a stream or valley along its north or east side, as it may be sunnier and drier there. 'Ibis is due to the angle of the sun. '!he south or west side of a valley may remain in shade for m::>st of the day. 4. Use the raised bench along a stream, if there is one, rather than the edge of the stream itself. If the bench is raised high enough above the water table to be dry, it will be drier than the edge of the stream. 5. Cross a stream at its driest plant association. Avoid crossing at a wet association. Wet plant associations are common along streambanks, but are easily damaged.

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6. Approach lakes and ponds fran their driest and highest side. Use plant associations and elevation differences as a guide. Often the downhill edge of a lake will have a boggy area. 'Ibese boggy areas are fragile and should be avoided. 7. Choose exposed ridgetcps rather than protected ones as vista vantage points. Plant associations will be dry there and vegetation thinner, providing better opportunities for long distance views. Vegetation will be less fragile there, and the trail will be drier. 8. Provide a variety of aspects, plant associations, trail grades, and positions within one day's travel to increase user enjoyment of the trail. 9. Cross a stream or route the trail witin 100 200 feet of a stream within a half day's travel to provide access to drinking water if no other source exists. '!be best and purest stream water for drinking is obtained where the water is rooving quickly. '!be safest place to cross a stream is where it is wide and shallat1. Try to find a place to cross which has both good crossing and easily accessable drinking water close by. 10. Provide opportunities for long distance panaramic viewing fran high vantage points, for scenic value and hiker orientation. Hiker orientation is especially important as the trail gets farther away fran its beginning point. 18

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11. Avoid routing trails in proximi. ty to kna wildlife nesting, denning, or birthing sites. Human activity can disturb wildlife by interfering with crutial breeding and young-rearing habits. This can became dangerous for the user, and jeopardize the success of sane species' ability to reproduce. 12. Avoid routing trails through dense shrubland and kna riparian feeding sites in bear country. Bears are unpredictable and may attack with little or no provocation. 13. Avoid routing trails over very loose rock. This can be extremely dangerous, resulting in personal injuries and rockslides. If a trail must have a grade over 15% 20%, route it over very stable rock or rocky soil. 14. Do not create any new trails above timberline. The tundra is extremely fragile and takes generations to revegetate. If trail routing cannot avoid close proximi. ty to tundra, route the trail to cane closest to tundra where the tundra ccmmmi.ties are dry meadow types. catpletely avoid snowbank and rooist meadow tundra camruni ties. 15. Any stretches of trail which are unavoidably likely to cause maintenance problans should be located as close as possible to access points which are accessible by vehicles. Tradeoffs in the design of a trail: Any trail system is only as satisfactory as the degree to which it satisfies the 19

PAGE 22

user. It is :inp:>rtant that the designer foresee the users' needs and attempt to fulfill than as closely as possible. care should be taken to provide variety in all aspects of the design. To design a trail which has very little impact on the landscape, yet is uninspiring to the user is a big mistake. 'Ihe trail may not be used at all. Or, users may create their own trail network to achieve their desired goals. In both cases, an opportunity has been missed. It is far better to design trails which have little impact on the land and also provide an exciting hiking experience. Sanetimes it is desireable to foresake minimum impact for a heightened user experience. For example, it may be desireable to provide several stretches of steep trail grades to break up an otherwise boringly level trail. Perhaps it may be desireable to lead a trail through a stretch of lush, shady forest vegetation to break up the monotony of a sunny meadc:M trail. If the trail does not provide enough variey on its own, users will seek that missing variety off the trail. 'Ibis defeats the purpose of a trail: to get users where you want them to go and provide them a good time getting there. 20

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SICI'IC6 V An OVerview of Relevant I.aiXlscape Cllaracteristics SOilS Soils are made up of different sized particles, including sand, silt, and clay. Sand is considered those particles 2mm .05mm in size, silt is .05mm .002mm, and clay is any particle smaller than .002mm. The size of soil particles plays an important role in how those particles behave. Clay particles are the tiniest mineral flakes of their parent rocks -the end product of extensive weathering. They are highly active chemically and bond easily to other particles, chemicals, and water. Sand grains are those particles nost resistive to weathering forces, and thus are quite chemically inactive. Silt are those particles intennediate in size and weathering between clay and sand, and are also chemically inactive. Sand and silt particles in a soil function as skeletal material, whereas clay and other colloids, such as organic matter, provide all chemical activity in that soil. The relative proportions of different sized particles in a soil determine its textural class. The name of a textural class relates to the predominant size of particles present or manner in which the soil behaves. When sand, silt, and clay and their properties are all represented, the texture is a loam. Figure 1. depicts textural classes by proportion of particle sizes. (27) Note that a sand can contain up to 10% clay particles, whereas a clay can contain as little as 40% clay particles. Soils with high percentages of sand or gravel are tenned Coa.rse soils. Those soils with high percentages of clay are tenned fine soils. See the following chart for canparison. (27) 21

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Figure 1. Soil Textural Classes. From The Nature and Property of Soils by Brady. 100% 0 10 70 80 70 60 50 40 30 20 10 sand PERCE N T SAND F 1 G u R E 3 : 5 . Relationship between the class name of a soil and its particle size di stri bution . In using the diagram the point s cor responding to the percentages of silt and clay present i n the soil under consideration are located on the silt and clay lines , respectivel y . Lines a re then projected inward, parallel in the first case to the clay side of the tri angle and in the second case parallel to the sand side . The name of the compartment i n which the two lines intersect is the class nam e of the soil in question . Basic Soil Textural Ccmron Name Texture Class Names Sandy soils Coarse Sandy Uxmty sands coarse Sandy loam Fine sandy loam Very fine sandy loam I.oams Medium IDam Silt loam Silt Clay loam M::xi. fine Sandy clay loam Silty clay loam Sandy clay Clayey soils Fine Silty clay Clay

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Although not indicated in the soil textural class, organic matter may be present in the soil. Organic matter is very active chanically, and in rooderate quantities can alter a soils's physical properties, mostly to the better. The different sized particles in a soil determine its physical peoperties. Particles in a sand lie close together, creating few, large pores. This arrangerent contributes to good aeration, drainage, permeability, and rapid infiltration of water. The chanical inactivity in a sand contributes to low water-holding capacity and fertility. Conversely, particles in a clay lie together loosely, surrounded by nurrerous, small voids. Clays tend to have poor aeration, drainage, permeability, and slow infiltration; yet have high water-holding capacity and fertility. ( 27 ) Figure 2. sUI'CIPai'izes these properties. The processes of erosion and oampaction are directly influenced by a soil's texture. Figure 2. Properties of sand and clay. Sand good drainage good aeration good pemeability fast infiltration low water-holding low fertility Clay poor drainage poor aeration poor permeability slow infiltration high water-holding high fertility

PAGE 26

Soil Erosion by Water Soil erosion caused by rainfall is a function of several factors: intensity and duration of storms, anount of debris or vegetative cover, degree and length of slq?e, and texture of the soil. ( 27) '!he erosion process begins when a raindrop hits the ground. If there is litter or vegetation growing, this cover absorbs the physical i.Jll:>act of the raindrop, prior to contact with the soil. If there is no cover, the physical force of a raindrop 1 s ilrpact disperses fines on the soil surface. Very fine sand is the most easily dispersed, followed by clay and silt. Clay particles, being highly active chemically, tend to bond to each other, as well as to silt and sand. Strong aggregates of clay can form in a soil 1 s structure which are quite resistant to dispersion. ( 28) Once dispersed, however, clay particles flow into and clog soil pores, rendering the soil surface impervious to infiltration. (28) After hitting the ground, the raindrop infiltrates the soil surface and moves down through the soil. '!he speed at which water enters the soil (its infiltration rate), the ease with which water moves down through the soil (its penneabili ty) , and slq?e, together determine the anount of rainfall absorbed. Rainfall not absorbed runs downslope, carrying any dispersed fines. Water 1 s mechanical ability of transport is proportional to its velocity. ( 34) Only fine particles can be moved at low velocities, while very huge boulders can be moved at very high velocities. '!he velocity of water flowing downslope increases with the degree and length of slope. (34) 'lherefore, very fine sand, clay, and silt can be carried much further than can sand or gravel. 24

PAGE 27

Soil erosion potential can be determined by use of the Universal Soil Loss Equation. The USLE was developed by Wischrneier in 1965 to determine potential arrounts of soil lost to water erosion. (27) The equation quantifies the physical factors of stonn damage and land resistance as they influence arrount of soil lost in runoff. The Universal Soil Loss Equation is: A= RxKxLxSxCxP where: A = soil loss (tons per acre) R = the soil erosivity index (erosivity of storms) K = the soil erodibility index L = the hillsl6pe-length factor S = the hillslcpe-gradient factor C = the cropping-managerrent factor P = the erosion-control practice factor Soil Catpaction The degree to which a soil will c:xmpact is a function of how close together its particles are and the arrount of water present. The c:xmpaction of a soil is expressed as its bulk density. Bulk density is a measure of weight per unit volurre of a soil. (27) In a coarse textured soil, such as IOOstly sand, the large particles are pulled close together tmder their CMn weight. These coarse soils have a high bulk density. Conversely, the clay particles of a fine textured soil have a lower bulk density than coarse soils. Under applied loading, however, fine particles rearrange, and due to their platy shape, can becane much 100re dense! y packed than can coarse particles under the same pressure. (27) The addition of water to a fine textured soil lubricates and loosens the arrangerrent of clay particles, causing them to becane partially aligned. Under loading the clay particles in these wet soils c:xmpact further, and much 100re readily, than when they are dry. Figure 3. illustrates the range of bulk density and oampactness of differently textured soils. (27)

PAGE 28

...... (") 1 .75 () ...... " ...... ..... CJ) c:: Q.) 0 .:::J:. ::J co 1.50 1.25 I 1 coarse (sand, sandy loam) +--Itfine (silt loam, clay) very loose Compactness Fi1ure 3. Bulk Density of Soils. very tight Relative positions on a well developed hillslope are depicted in Figure 4. (38) '!hey are: the sunmit of the hill or ridge; the shoulder, which lies just downhill of the summit and before the slope of the hill begins to steepen; the backslope, which is the steepest part of the hill; the footslope, where the slope of the hill begins to flatten out; the toes lope, which is the transition between the footslope and the valey bottan; an the valley bottan, which is the flattest land between two hills. 26

PAGE 29

Fig1re 4. Hillslope Positions. From Geomorphology by Ruhe. Su -summit Bs -backslope Sh shoulder Fs footslope P -pediment As a very general trend, differences in soil texture and m:>isture are related to position. (38, 42) Soils of a locale tend to be very similar throughout due to similarity of underlying geology. However, same differences in texture are likely to be found between the surrrnit and toeslope of a (38) In Colorado, many ridges have sandstone intrusions toward the sumni. ts and shale intrusions nearer the ( 42) Sandstones weather to ooarser soils and shales weather to finer or clayeyer soils. (42) In addition, the weathering process accentuates this difference. Fines fran the higher positions on a slope are carried downhill in runoff and deposited at the foot of the Being m:>re level there, m:>isture takes longer to dry up and continues to weather the soil fragments further into finer particles. (38) In general, soils nearer the sumni. t of a tend to be ooarser than at lower positions. (42) Finer soils may typically be found on the m:>re level terrain of a or valley bottan. However, due to irregularities of topography, parent materials, and weathering, any texture of soil may appear anywhere on a (42) 27

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SOIL MJIS'IURE REX3IMFS Texture of a soil as it relates to infiltration and permeability partially detennines the moisture content of that soil. In general, sands have higher infiltration rates than do learns or clays. (27, 28) other factors determining the soil moisture regime of a loeation are aspect, wind, precipitation, and underlying geological features. (29) 'lhe steeper the slope, the less water infiltrates and the more runs off. Snow accumulating on southerly and westerly aspects melts faster than on northerly or easterly aspects due to the direct rays of the sun. Soil in areas exposed to the wind dry out faster fran evaporation. Plant associations occur in particular habitats partly in response to the moisture regime provided there. (29, 23, 24) In general, dry plant associations tend to occur: on exposed and windy sites, little snow accumulates or blows off early, coarse soils, steep grades, and south or west aspects. Conversely, moist plant associations tend to occur: on protected sites, where snow accumulates or stays longer, finer soils, gentler grades, and north or east aspects. Wet plant associations tend to occur where the water table is near the grO\IDd surface, on poorly drained sites, and where snowxrelt runoff inundates the grO\IDd for prolonged periods. ( 25) 28

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SECl'ICfi VI Finding OYerall '1'1:'arJt>li.ng Resistance and Trail Ux:atioo Suitability The key to most suitable trail locations lies in determining landscape types which are most resistant to the effects of trampling. This involves analysis o f the trail surface itself -of the soils and trail grades, as well as the trail margins -or the surrounding vegetation. The following process was used to determine trampling resistance and then trail location suitability. Resistance of Trail SUrfaces Resistance of trail surfaces was determined by analysis of soil texture and trail grade as they relate to soil erosion. SOIL RESISTANCE 'ID EROSIOO Resistance to soil erosion was determined by use of the Universal Soil Loss Equation. The equation is: A=RxKxLxSxCxP where: A = soil loss (tons per acre) R = the soil erosivity index ( erosivity of stonns) K = the soil erodibility index L = the hillslope-length factor S = the hillslope-gradient factor C = the crcpping-manageroent factor P = the erosion-control practice factor. This study looks at the variables of soil erodability K, and hillslope length and grade L/S. All other factors -stonn characteristics, croppingmanageroent, and erosion-oontrol practice (R, C, and P respectively) -are considered constants which do not affect the soil erodability of wilderness trails because of extremely low rnanageroent intervention in the wilderness setting. K values (soil erodibility) have been established by the Soil 2 9

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Conservation Service. (43) K values reflect a soil's infiltration rate, permeability, and structural stability, which in turn detennine the soil's ercxlibili ty. K values are assigned to soil textures as follc:Ms: sands sandy learns clays clay learns silt learns .15 .20 .24 .28 .32 .17 .24 'Ihe K value used for sand was .16, and .22 was used for sandy loam. 'Ihe L/S value is the canbined effect of slope grade and length. For this study, the arbitrary trail grades selected were: 3%, 6%, 9%, 12%, 15%, 20%, and 30%. Trai l slope length was selected to be 100 feet. Values for these various trail slope grade/lengths were read fran the L/S chart which follc:Ms and are: 3% .03; 6% .065; 9%-1.20; 12%1.75; 15%-2.50; 20%-4.0; 30% 7.5. (34) >< "' "0 c: ... 0. 0 .c 00 c: u -I 0 . 5 --'2.------, __ 1------(). ) 1<;....---0 . 2 ---------------1---0 . 1 .... --1 < ..-;-1 I I I I I I I 0 20 4 0 Ml I 0 0 200 400 600 I 000 2000 H illslopc l e n g th (feet) Figure 15-19 Chart for eval u atinu the: length s lope facto r . LS, i n the Univer sal Soii-L'"' Equation. The so lid line s conditions within th e range of d a t a from which curve s were derived . The dashed lines arc: ba s ed o n extrapolations a n d should be ... fl=rnm I I<; <;oil C'onservati o n Service 1975b. )

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As per the USLE, K values and L/S values were multiplied. Their sums indicate relative erodibility of trails on different soil textures and of different grades. See Table 1. Table 1. K and L/S Sums sandy loams/ saroy clay silt sands loams clays loams loams K value .16 .22 .24 .28 .32 Grade L/S value .03 .0048 .0066 .0072 .0084 .0096 3% .065 .0104 .0143 .0156 .0182 .0208 6% 1.20 .1920 .2640 .2880 .3360 .3840 9% 1. 75 .2800 .3850 .4200 .4900 .5600 12% 2.50 .4000 .5500 .6000 .7000 .8000 15% 4.0 .6400 .8800 .9600 1.1200 1.2800 20% 7.5 1.2000 1.6500 1.8000 2.1000 2.4000 30% 30% @ 14.0 2.2400 3.0800 3.3600 . 3.9200 4.4800 3001 17.0 2.7200 3.7400 4.0800 4.7600 5.4400 5001 u.s. Forest Service trail grade and length guidelines were included for canparison. The Forest Service reccmnends trail lengths of 1001 , 3001 , and 5001 on 30% grades for trails of increasing difficulty, suitable for wilderness awlications. ( 36 ) :U:West sums represent highest resistance to erosion. For canparison, grades and soil texture were listed in order of resistance to erosion fran lc:Mest sum to highest. See Table 2. 31

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Table 2. Soil Ranking by Sums Rank Grade Texture Sum L/S K l 3% sands .0048 .03 .16 2 3% sandy learns .0066 .03 .22 3 3% clays .0072 .03 .24 4 3% clay learns .0084 .03 .28 5 3% silt learns .0096 .03 .32 6 6% sands .0104 .065 .16 7 6% sandy learns .0143 .065 .22 8 6% clays .0156 .065 .24 9 6% clay learns .0182 .065 .28 10 6% silt learns .0208 .065 .32 11 9% sands .1920 1.20 .16 12 9% sandy learns .2640 1.20 .22 l3 12% sands .2800 l. 75 .16 14 9% clays .2880 1.20 .24 15 9% clay learns .3360 1.20 .28 16 9% silt learns .3840 1.20 .32 17 12% sandy learns .3850 l. 75 .22 18 15% sands .4000 2.50 .16 19 12% clays .4200 l. 75 .24 20 12% clay learns .4900 l. 75 .28 21 15% sandy learns .5500 2.50 .22 22 12% silt learns .5600 l. 75 .32 23 15% clays .6000 2.50 .24 24 20% sands .6400 4.00 .16 25 15% clay loams .7000 2.50 .28 26 15% silt learns .8000 2.50 .32 27 20% sandy learns .8800 4.00 .22 28 20% clays .9600 4.00 .24 29 20% clay learns 1.1200 4.00 .28 30 30% sands 1.2000 7.50 .16 31 20% silt learns 1.2900 4.00 .32 32 30% sandy learns 1.6500 7.50 .22 33 30% clays 1.8000 7.50 .24 34 30% clay learns 2.1000 7.50 .28 35 30% silty loams 2.4000 7.50 .32 1 300' sands 2.2400 14.00 .16 2 500' sands 2.7200 17.00 .16 3 300' sandy learns 3.0800 14.00 .22 4 300' clays 3.3600 14.00 .24 5 500' sandy learns 3.7400 17.00 .22 6 300' clay loams 3.9200 14.00 .28 7 500' clays 4.0800 17.00 .24 8 300' silt loams 4.4800 14.00 .32 9 500' clay loams 4.7600 17.00 .28 10 500' silt loams 5.4400 17.00 .32 3 2

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TRENDS IN EROSION RATES Sums of the K and L/S values were then plotted on a graph to determine trends in the change in rates of erosion. See Figure 5. As expected, each incremental increase in grade prcduced an increase in the rate of erosion. 'Ihree general trends anerged. Rates increased sla.vly but steadily up to 9%, at which point the curve started to increase rapidly. Nine to twelve percent grades are a transition stage, the beginning of a dramatic increase in the curve. The high resistance of the (X)(rrser soil textures relative to finer textures is illustrated in this part of the curve. Note that a sand on 12% grade is slightly more resistant than a clay, and considerably more resistant than a clay loam or silt loam on a 9% grade. Note the very slight difference in erodability between 9% silt loam, 12% sandy loam, and 15% sand. This trend of sands and sandy loams showing higher relative resistance to the finer textures continues throughout the curve. HcMever, nowhere else is the discrepancy so great as it is in the 9 -12% range. At 12% the curve begins to rise very sharply, and at about 30%, skyrockets. Note that even at 30% grade, a 300-foot stretch or trail on sandy soil is still more resistant than a 100-foot stretch of trail on a silty loam. Erosion resistance of all soil textures on grades above 12% is extranely la.v relative to the gentle grades, by as much as a thousandfold. The Forest Service recamrnends wilderness trail grades of 30% for stretches of 100', 300', and 500' for standards of increasing difficulty. {36) These are very steep trails which cut at sharp angles to the contours. calculations for ercdability on these trail scenarios were included for canparison. Note that these trails are ten to twenty times more ercdable than a 100-foot trail stretch on 12% sand. Clearly these trails pose a maintenance problem if used 3_3

PAGE 36

extensively. It is this author's opinion that there is no need to provide such erodable trails on soil when 30% ascents can be made over rock. TRAIL GRADES RESISTAOCE 'ro EROSION Fran the graph, relative resistance to erosion was noted as follows: highest below 3% high to moderate 3% -6% moderate 6% -9% low 9% -12% extremely low 12% 30% and above 'lbese levels of resistance form the ranking of trail grades and soil textures to be canbined with vegetative resistance later on. See Table 3. Table 3. Soil Resistance to Erosion on Trails SOIL TEX'IURE Highest Resistance sands sandy learns clays clay learns silt learns TRAIL GRADE 0% 0% 0% 0% 0% High to M::xlerate Resistance sands 3% sandy learns 3% clays 3% clay learns 3% silt learns 3% sands 6% TRAIL SI.DPE 100' " " " " 100' " " " " "

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Table 3. continued SOIL TEX'IURE f.b:ierate Resistance sandy loarns clays clay loarns silt loarns sands l.<::M Resistance sandy loarns sands clays clay loarns silt loarns sandy loarns sands clays 'mAlL GRADE 6% 6% 6% 6% 9% 9% 12% 9% 9% 9% 12% 15% 12% Extranel y l.<::M Resistance clay loarns 12% sandy learns 15% silt loarns 12% clays 15% sands 20% clay loams 15% silt loams 15% sandy loarns 20% clays 20% clay loarns 20% sands 30% silt loarns 20% sandy learns 30% clays 30% clay learns 30% silt loams 30% SOIL TEX'IURE SLOPE LENGTH sands 300' sands 500' sandy loams 300' clays 300' sandy loams 500' clay loams 300' clays 500' silt loams 300' clay loams 500' silt loams 500' TRAIL SLOPE LENGTH " " " II " " II " n II II II SLOPE GRADE 30' n " " " n " " " "

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Resistance of Trail Mirgins Resistance of trail margins to trampling is determined by analyis of vegetative fonn and soil moisture. VEX:;E"mTIVE FORM Resistance to Trampling Damage Vegetative fonn partially detennines resistance of a plant species to being killed by trampling. Research sha.vs that certain morphological characteristics contribute to trampling resistance. '!bey are: renewal buds located at or bela.v the ground surface, numerous basal stems and leaves rather than single stems with leaves arising fran that stan, folded leaves, and tough, thicker leaves rather than thin, delicate leaves. ( 6, 7, 33) Grarrminoids are quite resistant to trarnpling, having nrultiple, basal stans and leaves, and renewal buds at the ground surface. Shrubs have fair resistance to trampling -having nurrerous basal stans and sare renewal buds at the ground surface. Many forbs are single starmed with leaves arising fran the stan, and have renewal buds well above the ground surface. In general, forbs have poor resistance to trampling. Potential to Spread into Margins Vegetative fonn also indicates the potential of a species to spread vegetativel y into denuded trail margins. Spreading or reproducing vegetatively has m:nnerous advantages over sexual reproduction. Vegetative reproduction saves time, and can take place independently of outside vectors. (23, 29) Gramminoids tend to spread very readily and have a good potential to revegetate denuded trail margins. Sare shrubs and sane forbs spread readily, but many of both do not. 'lberetore, shrubs and forbs have only fair potential to revegetate denuded trail margins. 36

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OVerall Suitability for Trail Margins '!be two attibutes of tranpling resistance and potential to spread into denuded margins together give an overall suitability for trail margins. Granminoids are best suited for trail margins, being highly resistant to tranpling and spreading readily into denuded areas. Shrubs have fair resistance to trarrpling, fair ability to spread into denuded areas, and only fair suitability for trail margins. Forbs are quite unsuitable for trail margins, with poor resistance to trarrpling and only fair ability to spread into denuded areas. See Figure 6. for the ranking of these vegetative forms. Figure 6. Vegetative FormTrail Margin Suitability. Vegetative Qualities Resistance to Trampling Potential to Spread into Margins Overall Rating Suitability for Trail Margins Vegetative Form Gramminoid I Good Good Good Best 37 Shrub Fair Fair Fair Fair I Forb Poor Fair Poor Unsuitable

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SOIL M:>ISTURE Research on wilderness trail conditions shows that soil moisture content and moisture regime of a species' habitat directly affects its resistance to tranpling. ( ( 3, 6, 7, 8, 9, 22, 33) Trails going through dry rreadows or open forests showed less damage to tranpling than trails through shady, moist, and closed forests with lush forb understories. ( 3, 6, 7 ) Perhaps this resistance in the drier habitat plants is due to their lower water content, and therefore, less rigidity of tissues. 'Ibe drier soil is better drained and so canpacts less under tranpling pressure. (27) The less canpacted soil contributes to increased aeration and vigor of the plant's root system, as well as to better root penetration and spreading ability. ( 27, 28) Wet soils canpact under loading, and experience breakdown of structure, making them canpletely unsuitable for trails. TRAMPLING RESISTANCE 'Ibe cx:rnbination of vegetative fonn and soil moisture regi.Ire together provide a plant community with overall resistance to trampling. Dryness provides the most resistance, wetness the least, and moistness an intennediate value. See Figure 7. Drainage Vegetative Form Gram I Shrub I Fori) Gram I Shrub I Forb 1 Gram l Shrub I Forb Dry Meadows Very Good & Forests HIGH Moist Meadows GoodMod & Forests MEDIUM Wet Meadows Poor & Forests LOW

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Note that very well-drained, dry meadc::Ms and open forests have highest resistance to traJll)ling: well-drained, rroist meadc::Ms and forests have medium resistance: and poorly drained, wet meadc::Ms and forests have lc::M resistance. SUITABILI'IY FOR TRAIL lOCATION To determine suitability for trail location, the vegetative fonn/rroisture regimes are ranked for overall suitability for trail location. See Figure 8. Note that all torb and wet associations are unsuitable. A preference for dry associations over rroist was implemented due to a tendancy for drier associations to occur on coarser soils. These coarser soils have a higher resistance to erosion and canpaction. (27, 28) Thus, very well-drained, dry granminoid ccmmmities have highest suitability for trail location. Second best are dry shrub ccmnunities, followed by rroist granminoid ccmnunities, and then rroist shrub communities. Figure 8. serves as a rrodel for trail location suitability. Plant associations of any region or locale can be used with this rrodel to indicate their relative resistances to trant>ling and trail location suitabilities. Figure 8. Trampling Resistance Model. Drainage Vegetative Form Gram I 8tnt> I Forn I Dry I I I VMy Good 1 2 I i I I I I I GoodMod Poor Qram J 8hnb I Forb I BrMI I 8twlb I forb Moist 3 :. 39 4 I I I I I • I J I I I I I I e I :0 !! able I "3 I .. I :5 I I

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Plant associations of Colorado coniferous forests were inserted into their positions in the IOOdel, and thus, received ranking of their individual resistances to trampling and trail location suitabilties. See Figure 9. '!he plant associations are coded by botanic name, using the first two letters of genus and species. ( 26) capitalized letters indicate overstory tree species, and lower case letters indicate daninant understory species. For exanple: ABIA-PIEN caro stands for Abies lasiocarpa-Picea englemannii overstory with carex rossii understory. The c::cmron name for this plant association is subalpine fir-Englemann spruce/ross sedge. A list of Colorado conifer forest plant associations ranked for trail suitability appears in Appendix III. 40

PAGE 43

LarxifOllll am Trail Grade In general, trails of various grades are more likely to occur on particular hillslq>e positions. For exarrple, trails with grades of under 3% are most likely to be on nearly level ground, such as a surrmi.t, toeslq>e, or valley bottan. Trails with grades of 20% must be on a backslq>e. 'nlerefore, a general correlation can be drawn between possible trail grade and relative position on a hillslq>e. Figure 10. depicts most probable trail grades on relative hillslope positions. The range of trail grades are those which were selected to calculate soil loss. As expected, the location of trails with highest resistance to erosion would most likely be valleys, toeslq>es, and surrmi. ts. Foots lopes and shoulders would likely have high to moderate resistance to erosion, and backslopes moderate to low resistance to erosion. Figure 10. Trail' Grades/Hi 11 s 1 ope Positions. Probable Tran Grades on Hillslope Positions /0%-3% /3%-6% summit I ..,1 ov.t 0'&,. / (0%-6%) 6% -% /12%-20% 20%-30% /3%-6% I 0%-3% ;!"" /0%-3% 'OeaJop. I valey 41

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Scale of Trail IDcatial Suitability 'Ib identify most suitable trail locations on a hillslope, trail grades and hillslope positions are oambined with the model of resistant plant association types. 'Itle oambinations are ranked for suitability, incorporating a preference to dryness over moistness. See Figure 11. Hillslope Position/ Vegetative Form Trail Grade I Moist Gramminoid Dry Gramminoid Dry Shrub Moist Shrub Summit Toes lope 0%-3% 1 2 5 6 Valley Shoulder 3%-6% 3 4 7 8 Foot slope Back slope 6%-12% 9 10 11 12 'Itle result of this final ranking is the establistrnent of an overall scale of suitability for trail locations. 'Itle scale is as follCMs in decreasing order of suitability.

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SCALE OF TRAIL u:x:ATION SUI'mBILI'IY M::>st Sui table l. 0% 3% trails on surrmits, toeslopes, and valley bottans with !Y granminoid plant associations 2. 0% 3% trails on surrmits, toeslopes, and valley bottans with !Y shrub plant associations 3. 3% -6% trails on shoulders and footslq>es with .!y grantninoid plant associations 4. 3% -6% trails on shoulders and footslopes with !Y shrub plant associations 5. 0% -3% trails on surrmits, toeslopes, and valley bottans with rroist granminoid plant associations 6. 0% 3'% trails on surrmits, toeslopes, and valley bottans with rroist shrub plant associations 7. 3% 6% trails on shoulders and footslq>es with rroist grantninoid plant associations 8. 3% -6% trails on shoulders and footslq>es with rroist shrub plant associations 9. 6% -9% trails on backslq>es with .!y granminoid plant associations 10. 6% -9% trails on backslq>es with .!y shrub grantninoid plant associations 11. 6% -9% trails on backslopes with rroist grarrminoid plant associations 12. 6% -9% trails on backslq>es with rroist shrub plant associations least Suitable Field Descriptions of Scale IDeations SUITABLE u:x:ATIONS l. & 2. Nearly level, dry meadc:Ms or open forests with grantninoid or shrub understories Areas rrost suitable tor trail location are nearly level and dry. IDeations are typically on exposed ridges or mesa sumnits, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. 'Ibese are areas of lCM snCM accumulation or where snCM blc:Ms off early in the spring. 'Ibe soils 43

PAGE 46

here are very well drained with a relatively low ooisture content. '!bey tend to range fran rocky or gravelly soils to coarse learns. To minimize erosion, trails located in these areas should not exceed 3%. 3. & 4. Gently sloping, dry meadows or open forests with granminoid or shrub understories '!he second oost sui table areas for trail location have very gentle slopes and are dry. IDeations are typically on exposed ridge and mesa surrmits or shoulders, scree or rocky slq>es, or raised benches; and tend to have a southerly to westerly aspect. 'lhese are areas of low snow accumulation or where sncM blows oft early in the spring. '!he soils here are very well drained with a relatively low ooisture content. '!hey tend to range fran rocky or gravelly soils to coarse learns. To minimize erosion, trails located in these areas should not exceed 6%. 5. & 6. Nearly level, ooist meadows or forests with granminoid or shrub understories '!he third most suitable locations tor trails are nearly level and relatively ooist. 'lbese may be protected ridge surnni ts, toeslopes or valley bot tans. Typical locations my be streamsides, lake margins, draws, benches, or meadows. Also included are areas protected fran extrane sun or wind. Aspect may be northerly to easterly, especially where little snow accumulates; or southerly to southwesterly where snow tends to accumulate. Soils are well drained and tend to range tran gravelly and sandy loams to sandy clays. To minimize erosion i n these areas, trail slq>es should not exceed 3%. 44

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7. & 8. Gently sloping, JOOist meadc:Ms or forests with gramninoid or shrub understories The tourth JOOst suitable trail locations for trails are gently sloping and relatively JOOist. These may be protected ridge sumri.ts or shoulders, or footslcpes. Typical locations may be streams ides, draws, benches, or meadc:Ms. Also included are areas protected fran extreme sun or wind. Aspect may be northerly to easterly, expecially where little snc:M accumulates, or southerly to southwesterly where snc:M tends to accumulate. Soils are well drained and tend to range from gravelly and sandy learns to sandy clays. To ndnirrdze erosion in these areas, trail slcpes should not exceed 6%. 9. & 10. Sloping, dry meadc:Ms or open forests with gramninoid or shrub understories. The titth best locations for trails are m:xlerately sloping and dry. These are backslcpes and draws. Typical locations may be exposed or windswept slopes and may tend to have a southerly to westerly aspect. These are areas of lc:M snc:M accumulation or where snc:M blc:Ms off early in the spring. The soils here are very well drained with a relatively lc:M JOOisture content. They tend to range fran rocky or gravelly to cx:>arse learns. To ndnirrdze erosion, trails located in these areas should not exceed 12%. 11. & 12. Sloping, JOOist meadc:Ms or open forests with gramninoid or shrub understories The sixth JOOst suitable locations for trails are m:xlerately sloping and moist. These are backslopes and draws. Typical loactions may be northerly or easterly 45

PAGE 48

slopes and draws where little snow accumulates, or southerly to westerly slopes and draws where snow tends to accmnulate. 'lbese are areas protected fran extrane wind descication. Soils are well drained and tend to range fran rocky and coarse loams to finer loams. To minimize erosion, trails located in these areas should not exceed 12%. UNSUITABLE u:x::ATIONS FOR TRAilS A. Steep trail grades and exterxied slope lengths Steep slopes or terrain which requires trail slopes to exceed 12% for prolonged stretches are unsuitable due to excessive soil erosion. Erosion increases with both grade and slope length. On trails of 12% slope and. steeper, maintained for 100' , erosion increases dramatically. Trails may be located on slopes which are greater than 12%, but the slope of the trail should not exceed 12%. B. Wet sites Wet sites are unsuitable due to the extranel y low resistance of the soil and vegetation to trarrpling. Trarrpling on a saturated soil canpacts it and destroys its structure. '!his diminishes the soil's resistance to erosion as well as decreases ease ot root penetration. In addition, plants growing in saturated conditions tend to have a high water c:x:mtent in their tissues, and thus are very likely to be broken upon tranpling. 46

PAGE 49

C. Forb-daninated understories Forb understories are unsuitable due to the low trampling resistance of the vegetative fonn of many torbs. Many forbs have single steros with leaves arising fran the stan. 'Ibis form has been noted to be the least resistant to trampling. Guidelines Guidelines are drawn up tran the preceeding scale of trail suitability. Although derived exclusively tran landscape resistance to trampling, these guidelines also inoorporate an elanent of user experience. 'lbe guidelines will assist the trail designer in locating trails for minimal trampling i.n"pact. 'lbe guidelines describe proceedures for trail oorridor identification which can be used on the drawing board and those which can be used in the field. 'lbese guidelines appear in Section VI. 47

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PART II: CASE S'lUDY '!he case study of this thesis applies the previously generated guidelines for minimum ilrpact trail location to design a trail system on an actual site. '!he case study is Huston Park Wilderness Area, which is in the Medicine BcM National Forest of Wyaning. Huston Park was selected fran many wilderness areas in Colorado and the i.mnediate area. It was necessary to find a site which had its vegetation and soils mapped. At the time of this project, Huston Park had the nost canplete resource inventory of any wilderness area in Colorado or Wyaning. '!he trail system of Huston Park was designed in two parts. First, the Continental Divide Trail corridor was designed. Second, the existing trail network was evaluated for its suitability of trail locations. Suitability of trail location was based on fragility of margin vegetation and erodability of trail soils. Any sections of trail on which the vegetation was determined to be too fragile or soils excessibely erodable were reoc:mrended to be revegetated. General Background of the Area '!he Medicine BcM nountain range extends fran northern Colorado into southern Wyaning. Huston Park Wilderness Area is at the northern edge of the nountain range. laramie, Wyaning lies to the east, about 30 minutes by car. '!here are two highways in the vicinity. One runs north-south on the east edge of the Medicine Bc:Ms. 'Ihe other cuts east-west through the nountain range just south of Huston Park. '!he Medicine Bc:Ms are a major recreation area for laramie and the northern front range of Colorado. Huston Park covers roughly 34,000 acres, and is about 12 miles by 4 miles in 48

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di.nension. '!he Wilderness Area encanpasses a massive uplift caused by the Continental Divide as it winds through the area. '!he Continental Divide is quite high in this area, but it is not rugged. Elevation of the area ranges fran 8-,600 feet at its western edge to 10,444 feet at the highest point on the Divide. Timberline occurs at about 10,200 feet in elevation, canpared to 11,000 feet at Denver's lattitude. '!here is roughly 250 feet of land above timberline. '!he uplift is quite flat on fonning a series of high elevation parks. 'lhese are expansive grassy areas with clusters of tree islands. '!he landform catches a oonsiderable arrount of precipitation, and the vegetation is relatively IOOist. '!he vegetation consists mainly of Englanann spruce and subalpine fir, with sane aspen and lodgepole pine. '!he top part of the uplift, being flat and wet, oonsists of extensive boggy areas daninated by wet forb associations. There are numerous small lakes scattered throughout the area. '!he uplift forms the headwaters of several rivers, IOOst notably the North Fork of the Encanpnent River. The Continental Divide enters at the middle of the northern boundary, winds through the area in a southeasterly direction, and exits at the middle of the southern boundary. Several trails and stock driveways run through the site. A major trail runs east-west just south of the northern border. 'IWo trails run north-south through the area. One runs down the middle of the area and the other at about the eastern one third mark. The Continental Divide Trail '!he Continental Divide National Scenic Trail is a planned, but not yet designed, trail which will follow the Continental Divide through the United States fran 49

PAGE 52

the border with Canada to the border with Mexico. It will go through Montana, Wyaning, Colorado, and New Mexico through federal, state, and private lands. When built, the Continental Divide Trail will be the Rocky Mo\IDtain equivalent to the Pacific Coast Trail or the Appalachian Trail. DESIGNIOO THE CONTINENTAL DIVIDE TRAIL 'Ihe main design criteria for locating the Continental Divide Trail is that is llUlSt cane within two miles of the Continental Divide. An attempt was made to create as much variety along the trail as possible. 'Ihe trail was designed to incorporate a variety of plant associations, hillslope positions, and grades. MAPPIOO STAGE Vegetation and soil data were obtained fran the Forest Service at the Hayden Ranger District in Encanpnent, Wyaning. Vegetation and soil maps were at the scale of 1:24000. All subsequent mawing and designing of the trail system was done at the same scale. Vegetation Plant associations were mapped using the ranking system fran the guidelines. Dry gramni.noids were located in the southwest portion of the site. Dry shrubs occupy a sizeable area on the east border. Moist shrubs occur in scattered patches over the southern part of the site. Moist gramni.noids cover the vast majority of the site. Wet forbs daninate a large area on the flat top of the site. Any new trails must avoid this boggy area. s o

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Soils Finer loams occur in large patches or narrc:M fingers over the site. The majority of the site's finer soils occur on the flat uplift. Fingers of fine loam follc:M drainages uphill. These highly erodable soils will pose a constraint to trail grades. Hillslope Position 1-t:>st of the leveler ground on the site is contained within the flat sUIIltlit of the uplift. Very little area is considered flat bottanland. The hillslope position map emphasizes the arrl extent of the uplift. Destination/Access The site's numerous small lakes are probable destination points. 1-t:>st of these lakes lie on or close to the flat area and within the sUIIltlit of the uplift. The existing trails on the site are also potential destination points. Access is provided at eleven points armmd the boundary. The entire western boundary is delineated by a trail. The eastern boundary is fonned by two roads. The eastern boundary is the site's rna jor access point. Constraints The constraints to trail location were mapped as a CCJrq?Osi te map. Constraints inclooed unsuitable plant associations, fine textured soils, destination and access points, hillslcpe positions, and the Continental Divide. Any trail must avoid unsuitable plant associations, and maintain a gentle grade over fine soils. The Continental Divide Trail must cane within two miles of the Continental Divide. 51

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Creating Internal Circulation -Linking Destination Points As per the guidelines, the trail was first routed through suitable plant associations, linking the destination points. Due to the nature of the trail, it was determined that the most appropriate form it should take is a single linear trail linking its northern and southern access points, with short spurs as needed. 'Ihe points where the Continental Divide enters and exits the site both became major destination and access points. Numerous small lakes becarre secondary destination points. 'Ihe trail was routed to cane within 200 feet of nine lakes along its course. '!Wo spur trails provide access to 4 more lakes. All of these lakes are in the higher elevations of the wilderness area. 'Ihe trail was designed to encanpasses a variety of vegetation types. It goes through meadows, shrubland, cp:m forest, and alpine meadow. It goes through moist granminoid, moist shrub, and dry shrub CCitTtUlili ties. For various stretches it skirts arotmd lush boggy ccmrnmi.ties. Using Hillsl Positions Second, circulation was designed to encanpasses a variety of hillslope positions. 'Ihe one hills lope position the trail lacks cc::rrpletel y is a true bott.anland. Due to the nature of the Continental Divide, it was i.npractical to route the trail out of the way to go down into a side valley. 'Ihe trail does, however, criss-cross a major draw toward the south end of the area. Due to the nature of the site, and requiranent to skirt the Continental Divide, the majority of the trail is along the surnnit of the uplift. 52

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Checking Trail Grade Appropriateness on Soil Textures Finally, the trail grades were checked to c:arply with the underlying soil textures. 'llle great majority of the trail lays atop finer textured soils • .Accx>rdingly, the majority of the trail is under 6% in grade. Trail grades go up to 15% in the few, and widely spaced sections over rock or coarse soils. Several major adjustments of the corridor were necessary to accc:mrodate the underlying soils. Locating the Centerline in the Field 'llle next step in locating the Continental Divide Trail would be to stake the actual centerline in the field. 'lllis planning process to locate the trail has successfully identified a corridor of maximum resistance to the of trampling. 'llle best final location can only be determined in the field, considering all surface conditions. THE CCN.riNTENTAL DIVIDE TRAIL SOCTIONS 'llle Continental Divide Trail is made up of five sections, each with its own character. 'llle trail is about 15 miles long and utilizes about 4 miles of existing trails. 'llle sections are described below. Section 1: Section 1 descends onto the site fran the northern boundary. 'lllis section of the trail is steep and utilizes an existing trail. Views of 2 major valleys are seen fran the higher portion of this section. 'llle trail skirts along a rocky area before enterring a noist meadow, and finally crosses the North Fork of the Encarrpnent River. 'lllis section is on a backslope with trail

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grades of 15%. Section 2: Section 2 picks up at the North Fork of the Encanprent River and rises gently as it progresses southward and U{Mard along the Continental Divide, until reaching the highest point in the area at 10,44 feet in elevation. 'Ibis section of the trail stays within 200 feet of the Continental Divide along its entire length, and passes by four alpine lakes. '.!he trail here is allrost entirely above timberline. 'Ibis is perhaps the IOC>st exciting stretch of trail due to its hillslope position. '.!he trail here lies on the edge of the summit of the uplift, with the land drq?ping off steeply to the west. To the east is the vast boggy area of the uplift. Views fran this stretch would be spectacular, particulary to the west. 'Ibis section of the trail is allrost entirely on finer learns, and trail grades are under 6%. Section 3: Section 3 starts at the highest point and descends gradually in a southeasterly direction. 'nle edge of the uplift is left behind as the trail crosses a high elevation park. Views fran this section are of IOC>untains in the foreground with the plains beyond. 'Ibis section of the trail passes by three small lakes with a spur to two IOC>re. Trail grades are all under 6%. Section 4: Section 4 starts out by crossing the Continental Divide and progress in a southerly direction. In this area the Divide becanes IOC>re of a defined ridge than a flat upland. Views fran this section of the trail are into Colorado to the south. 'Ibis section of the trail goes through IOC>re diverse vegetation than any other section. '.!he primary difference is the dry shrubland which lies just east of the Continental Divide. '!Wo small lakes are passed with spurs to two IOC>re to the east. 'Ibis section of the trail utilizes about two 5 4

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miles of existing trail. 'Ihe trail grades here are all under 6%. Section 5: Section 5 leaves the Continental Divide, descends down into a steep draw, and climbs back up to exit the site. 'Ihis section of the trail passes alternately through meadc:Ms and shrubland in very wide switchbacks. Trail grades in this section range fran belc:M 6% to 15%. THE WilDERNESS TRAIL SYSTEM All existing sections of trail within the wilderness area were evaluated for their suitability of location. '!his evaluation was based on resistance to traxrpling as detennined in this thesis. 'Ihe criteria were appropriateness of trail grade on underlying soils and resistance of the vegetation to traxrpling. Vegetation types considered too fragile to serve as trail margins were forbdaninated understories and poorly-drained boggy camumities. Trail grade and soil texture scenarios considered to have excessive erosion potential were trail grades over 6% on fine-textured soils, and grades over 15% on any soil type except very rocky soil. 'Ihere are no very rocky soils within the wilderness area. Any sections of trail which were unsuitable were reccmoended to be obliterated and revegetated. 'Ihe sections of existing trails are evaluated belc:M: Section A: Trail grades on Section A are appropriate to the soils and this section should remain. Section B: Trail grades on Section B range between 20% and 30%. 'Ibese 55

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grades are too steep and likely to cause severe erosion problems. Section B should be revegetated. Section C: Trail grades on Section C are all apprq>riate to the soils. 'Ibis section barely skirts the unsuitable boggy vegetation along the North Fork of the Encanpnent River. 'Ibis section should remain. Section D: Section D goes through the un.sui table boggy vegetation of the uplift and should be revegetated. 'Ibis vegetation is too fragile to support a trail. Section E: Trail grades on Section E are apprq>riate to the soils and this section should remain. Section F: Trail grades on Section F are apprq>riate to the soils and this section should remain. 'Ibis section forms part of the Continental Divide Trail. Section G: Trail grades on Section G are apprq>riate to the soils and this section should remain. Section H: z.t:>st of the trail grades on Section H are close to 15% and are too steep for the fine-textured soils. 'Ibis section should be revegetated. Section J: Section J is a new access trail to the system. z.t:>st of the 56

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Appendix I. The Wilderness Act of 1964. 78STAT.If-XJ . 78 STAT. 891. Publi.: l..tw HH-577 CJ.Hli(fL'" S . . j September 1%1 ANACf T u establish a National W ilderncss Preservation S}• srem for the pcrm anenr 1-uxl of rhe whole p.•>plc, and f or othe r purposes. Be it enacted by thl! So-'17ple in such manner as will le:tve them unimpaired for furure use and enjoyment as wilderrJeSS, and so as tu provide f ur the prortaion of these areas, the preservation of their wilderness ch:lraeter, and f o r the gathering and dissemination o f information regarding their use and enjoyment as wildemess; and no Ft*ra..llands shall be designated as ''wildemess areas" except as provided f o r in this Aet or by a subsequent Aet. (b) The inclusion of an are:t in rhe N ational WilderrJeSS Preservation System norv.• ithsranding. rhe are-.1 shall mnrinue ro be managed by rhe Department and agency having jurisdicrio n rheR'<.>Ver immetliarely bef ore irs inclusion i n the N ational WilderrJeSS Preservation System unless otherwise provided by Act of Congress . No appro priation shall be available for the payment o f expenses or salaries fur the administr ation uf the Narional WilderrJeSS Preservation Sysrem as a 5efX1r:lte unir nor shall any appropriati ons be available f o r additional per.;onnel stated as being required solely for rhe purpose of managing o r administering areas solely because they are included within the National WilderrJeSS Preservation System DEFINmoN OF WilDERNESS (c) A wiklerrJeSS, in contrast with those areas where man and his own works dominate the landscape, is hereby recognized as an area where the earth and irs communiry of life are untrammeled by man, where man himself is a visiror who does nor remain. An area of wilderness is funher defined ro me : m in this Act an area o f undeveloped Federal land retaining irs primeval characrer and influencr, without permanent improvements or human hab iotion, which is prorected and managed so as ro preserve irs nanlfal conditions and which ( l ) generally appears ro have been affroed primarily by rhe forces o f narure, with rhe imprint o f man ' s work substantially ll11Jl0ticeable; (2) has outstanding o:;>porrunities f o r solirude or a primitive and unconfined rype o f recre:trion; (3) has at least five thousand acres uf land or is uf sufficient size as ro make praeticable irs preserv atio n and use in an unimpaired mndi tion ; and (4) may also conoin ecologicll , grological , o r o ther fe:trures of scienrific, educational, scenic, or hisroricll value. NATIONAL WilDERNESS PRESERVATION SYSTEM-EXTENT OF SYSTEM Sec. ). (a) All areas within rhe national forests classified ar least 30 clays before rhe effective dare of this Acr by the Secretary of Agriculrure or rhe Olief of the Forest Servire as "wilderrJeSS", " wilJ",or "carot'" are hereby designared as wilderness areas. The Secrerary ol Agriculrure shall-

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(1) Within one year afrer the effective date o f this Aa, file a map and legal description of each wilderness area with the Interior and Insular Affairs Committees o f the U nired Stares Senate and the House of Representat ives, and such descri ptions shaU have the same fo= and effect as if included in this Aa: Prrn-ided, h oun•er, That rorrection of clerical and t)'JX>graphical errors in such legal descriptions and rrups may be made. ( 2 ) Maintain, available ro the public, rerords pertaining to said wilderness areas, including maps and legal descriptions , ropies of regulations governing them, ropies of public notices of, and reJX>rtS submitted ro wngress regarding pending additions, eliminations, or mcxiifications. Maps, legal descriptions, and ret,'Ularions pertaining to wilderness areas within their respective jurisdiaions also shall be available to the public in the offices o f regional foresterS, national forest supervisors, and forest {b) The Secretary of Agriculrure shall, within ten years after the enactment of this Aa, review, as to its suitability or nonsuitability for preservation as wilderness, eadJ area in the national forests classified on the effeaive dare of this Aa by the Secretary of Agriculrure or the Otief of the Forest Setvire as "primitive" and report his findings to the President. The President shall advise the United States Senate and House of Representatives of his reromrnend.ations with respect to the designation as "wilderness" or odler reclassification of each area on which review has been rompleted, together with maps and a definition d booniaries . Such advice shall be given with respect ro not less than one third of all the areas now classified as "primitive" within three years after the enactment of this Aa, not less than rwo-thirds within seven years after the enactment of Aa, and the remaining areas within ten years after the enactment of this Aa. Each rerommendation of the President for designation as "wilderness" shall bea:xne effective only if so provided by an Aa of Congress . Areas classified as " primitive " on the effeaive dare of this Aa shall rominue to be administered urder the rules and regular ions affecting such areas on the effeaive dare of this Aa until Congress has determined otherwise . Any such area may be increased in size by the President at the time he submits his recommendations to the Congress by rot more than five thoosa.M acres with ro more than one thousand two hundred and eighty acres of such increase in any one rompaa unit ; if it is proposed to increase the size of any such area by more than five thousand acres or by more than one thoosa.M twO hundred and eighty acres in any one rom pact unit the increase in size shall rot become effective until acted UJX>n by Congress . N othing herein rontai.ned shaU limi t the President in proposing , as pan of his recomrnend.ations to Congress , the alteration of existing boond.aries of prirnirive areas or reaxnrnecx!ing the addition of any rontiguous area of national f orest lands predominantly d wilderness value. Nocwithstanding any other provisions of this Act, the Secretary of Agriculrure may romplere his review and delete such area as may be neressary, but rot t o excaod seven thousand acres, from the southern tip of the Gore Range-Eagles Nes t Primitive Area , Colorado, if the Secretary determines that such action is in the public interest. (c) Within ten years after the effective dare o f this Aa the Secretary of the Interior shall review every roadless area o f five thousand contiguous acres o r more in the national parks, monuments and o ther units of the national park system and every such area o f , and every rood.less island within, the national wildlife refuges and game ranges, urxier his jurisdiaion o n the effective dare of this Aa and shall reJX>rt to the President his recommendation as ro the suitability or nonsuitability of ead1 such area or island for preservation as wilderness. The President shall advise the President o f the Senate and the Speaker of the House of Representatives o f his reromrnend.ation w ith respect t o the designation as wilderness of eadJ such area or island o n which review has been rom pleted, together with a map thereof and a definition o f its bound.aries. Such advice shall be given with respect ro not less than one third of the areas and islands to be reviewcrl under this subsection within three years after enaament of this Aa, rot less than two-thirds within seven years of enactment of this Aa, and the remainder within ten years of enactment of this Aa. A recommendation o f the President for designation as wilderness shall become effective only if so provided by an Aa of Congress . N o thing contained herein shall, by irnplicatim o r otherwise, be construed to lessen the present starucory authority of the Secretary of the Interior with respect to the mainrenance of rood.less areas within units of the national park sysrem. (d)( I ) The Secretary of Agriculture and the Secretary of the lnterior shall, prior to submitting any recommendations to the President with respect t o the suitability o f any area for preservation as wilderness( A ) give such public rot ice of the proposed aaion as they deem appropriate , including publicatiorr in the Federal Register and in a newspape r having general circulation in the area o r are-J.S in the vicinir:v o f the affected land; ( B ) hold a public hearmg or hearings at a location or locations convenient ro the area affeaai. 1he hearings shaU be announced throogh soch as the respective Secretaries involved deem app rop riat e , including mtices in the Federal Register and in newspapers o f general cinulation in the Classilicatioo. Prcsiiomi:U tion tO Coogrc5.'i. 78 Sf AT. R9l. 78 !>T AT. 81.)1 Rq1on to Prcsidrn t

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:"!STAT K'l2 . H K'JI . IIi USC ({, \2!\-\\l. 16 USC \77c 577h 16 usc H"'..:l 577h. .\9 Sut IIi USC I o!t 1eq. 41 Stat I(X):l. -l' J S101t 8 .\8. 7 8 Sf AT. 89:1. 7 R Sf AT. 894. area: Prm1Jt!d, Th . H if the lands involved are located in m ore rhan one State, a t least one hearing shall be held in e:JCh Stare i n whrn a portion of the land lies; (() at le-.J.St thirty days before the dare o f a hearing advise the Governor of each State and the governin g boord o f e-JCh mmty, o r in Alaska the oorwgh , in which the lands are located, and Federal deparnnents and agencies ronccrned, and invite such offcials and Federal agencies ro submit their views o n the proposed action ar the hearing or by no larer than thirty days following the date of the hearing . ( 2 ) Any views submitted 10 the a ppropriate Secretary under the provisions of ( 1) of rhis subsection with respect 10 any area shall be included with any m:omrnerxlations 10 the President and 10 Congress with respect ro such area. ( e ) Any modification o r adjustment of bourxlaries of any wilderness area shall be recommended by the appropriate Secreta!)' after puboc nocice of such proposal and puboc hearing or as provided in subsection ( d ) of this section. 1he propc.6ed modification or adjustment shall then be recommended with map and description thereof ro the President 1he Presdenr shall advise the United Stares Senate and the Hoose of Represent atives of his recommendations wirh respect 10 such modification o r adjustment and such recommendations shall become effective only in the same manner as provided for in subsections ( b ) and ( c ) of this sea ion . USE OF WILD ERNESS AREA S Sec 4. (a) The purposes of this Aa are hereby dedared robe within and supplemental 10 the purposes for which national f orests and units of the national park and national wildlife refuge systems are established and administered and-( 1 ) N othing in this Aa shall be deemed robe in intetfetok:e with the purpose for which national forests are established as set forth in the Act of June 4, 1897 (30 Stat 11 ), and the Multiple-Use Sustained-Yield Aa of June 12, 1%0 (74 Stat . 215). (2) N o thing in this Aa shall modify the resrraions and provisions of the Shipstead-Nolan Aa (Public Law 539 , Seventy-first Congress, July 10, 1930; 46 Stat 1020) , the Thye-Blamik Aa (Puboc Law 733, Eightieth Congress, June 22, 1948; 62 Stat 568), and the Humphrey-Thye-Blamik Andersen A a (Puboc Law (fJ7, Eighty-foorth Congress, June 22, 1956; 7 0 Stat. 326), as applying ro the Superior National F orest o r the regulations o f the Secretary of Agrirulrure. (3) Nothing in this Aa shall modify the statutOry authority under which units o f the national park system are created Further , the designation of any area of any park, monument , or o ther unit of the national park system as a wi.ldemess area pursuant to this Act shall in no manner lower the standards evolved f o r the use arxl preservation of such park, monument, or other unit of the national park system in acx:ordance with the Aa o f August 25, 1916, the statutory authority under which the area was created, or any other Aa o f Congress which might pertain ro or affect such area, including. but noc limited ro, the Aa of June 8 , 1>05 (34 Stat 225; 16 U.S.C 432 et seq.); section 3(2) of the Federal Power Aa ( 16 U.S.C 796(2)); and the Aa d August 21, 1935 (49 Stat 666; 16 U.S.C 461 er seq.). (b) Except as otherwise provided in this Act, each agerxy administering any area designated as wilderness shall be responsible for preserving the wilderness character of the area and shall so adrn.iMter such area for such other purposes for which it may have been established as also ro preserve its wilderness character. Except as cxherwise provided in this Aa, wilderness areas shall be devoted to the puboc p.uposes ci recreational, scenic, scientific, educational, conservation, and historical use. PROHIBITION Of CERTAIN USES ( c ) Except as specifically provided for in this Act, and subject to existing private rights, there shall be no commercial enterprise and no permanent road within any wilderness area designated by this Aa and, ccrept as !leU!SS3I)' to meet minimum !"e:jllirernents for the administration of the area for the purpose of this Aa ( irduding measures required in emergencies involving the health and safety of persons within the area), there shall be no temporary rood, no use of motor vehicles, mororized equipmentormororboors, no landing of aircraft, no o ther form of mechanical transport, and no struaure or installation within any such area. SPEOAL PROVISJONS (d) The following special provisions are hereby made: ( 1 ) Within wilJerness areas designated by this Aa the use of aircraft or rnocorboots, where these uses have already become established, may be pennittai to ronrinue subject to such resrraions as the Secretary ci Agrrurure deems desirable. In addition, such measures may be taken as may be in the ronrrol ci fire, insa-t:s and diseases, subject ro such roo::litions as the Secretary deems desirable.

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Appendix I. '!he Wilderness Act of 1964. 71! STAT. H'XJ 7l!ST AT tfJI l'ubl .. l..tw H1077 ClllWl"-' S . I S.:prl'mon I pic. and for other purposes . & it enaaed by tht! St!TldJe .mJ I l ouse of ufrhe United Sidle! uf Anum in .Ufembled, SHORT TIT I.E SECTION I. This A a m:Jy be citl..l as rhe "Wilderness Aa". WUJ 1ERNI _,, SYSlTM 1:.-..,"TAI\IJSHE!) STATI:MFNT Of I'Of.I C Y Sec. 2 . (J) In order m assu.rt' th.u an incn:asing population, by expmding and growing lllCS not o .. l."Upy and modify all areas within the Unired Stares and its leaving no lands dcsil'nated for preser. arion and pro(('aion in their narural rundirion. it is hc:rd'l)'dt-clarcd t o be the p:>li...y of the to S<.<."ure for d'lt' Amerion !X'Opk of pre s enr and future the: benefits u f an enduring rt'Sple in Stdl manner as will le-Jve them unimp-.1i.rcd for future use and enjoyment as wi!Jerr,(.-ss, and so tu provide for the: pmtt'llion o( tht:se areas, the preservation of their wilderness d=-.ICtt'f , and for the and dis.<;('lnination of information their use and enjoyment as wildemc:ss; and no Federal lands shall be Jes ignatt'll as "wik.lemess areas" except as provided for in chis Aa o r by a Aa. (b) 11'lt: indusiun of an an:J in thl Natit1nal Wilderness Preservation Sysn:m nt>rv.ithsr.lndinlo\. the an.J shal.l continue rube managt.J by the Deportrnem and agency having ju.risdiai o n then."ver immc.Jiarely before irs inclusion in the National Wilderness Preservation System unless ocherwise pmvik.gk:a.l. or other teJrurt.-s of scientific, educuional, SU11i<: . llr hismrical value . NAllONAI. VAllON Of SYSlTM St-c ). (.< ) AU are . .., wirhin dx n.Hillrwl f on'Sts cl:.Lssifi<,l ar k .... ,t .'>0 I St :rv iu: as .. w illi rr.;, ..... w iiJ". ' >r "c.uu: " an lx-n:by desiWJ.ited a.s wilJenl<:S.s artL\ The: ul Awi...ulrure shall-

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78SfAT. tm. 78 sr AT. sn is specifically auchori=l by Congress. GIFT'S, BfQUESTS, AND c.oNrRIBlJflONS SEC. 6. (a) The Secretary of Agriculture may aa::ept gifts or bequests of land w irhin wilderness areas designated by chis Aa foe preservari>n as wilderness. The Secretary o f Agriculture may also aa:epr gifts or bequests of land adjarenr ro wi.ldemess areas designated by chis Act for preservacion as wilderness if he has given sixty days advaoce rocice thereof to the Presi:lent of the Senate and the Speaker of the Hoose of Representatives . Lux! aa:epred by the Secretary of Agriulture under chis section shall berorne part of the wilderness area involvtd.. Regulati>ns wich regard ro any such land may be in aaordance wich such agreements, ronsistent wich the p:>li:y of this Aa, as are made at the rime of such gift, or such ronditions, ronsistent wich such p:>li:y, as may be incWed in, and aa:epted w ith, such bequest. (b ) The Secretary of Agriculture or the Secretary of the Interior is aurhori=l ro aa:epr private rontributi>ns and gifts to be used to further the purposes of chis Act ANNUAL REPORTS SEC. 7 . At the opening of each session of Congress, the Secretaries of .Agri:ulrure and Interior shall jointly report to the President for transrnissi>n to Congress on the statuS of the wilderness system, including a list and descriptions of the areas in the system, regulati>ns in dfect, and other pertinent information, together wich any re.:xxnmerx!arons they may care to malre. Approvc=d September 3, 1%4. LEGISLATIVE HISTORY : HOUSE REPORTS: No. 1538 aa:ornpanying H. R SXJ70 (Common Inrerior & Insular Affairs ) and No . 1829 ( Comm of Coufaaa:). SENATE REPORT No . 1(1) (Common Interior & Insular Affairs). ffiNGRESSION.AL REmRD: Vol 1(1) (1963): Apr . 4, 8, ronsidered in Senate . Apr . 9, ronsK!ered and passc=d Senate . Vol 110 (1964) : July 28, ronsidered in Hoose . July 30, ronsK!ered and passc=d Hoose, amended, in lieu of H . R SXJ70. Aug. 20, Hoose and Senate agreed ro ronference report. .t

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Appendix II. Wilderness Area Use Table 3 . Distribution of ,-.creatlonal uM and acr .. ge by claaalflcatlon atatua. Percentage of Total Acres and Total VlsltorDar_s For All Areas and Agencies Prim/title All Ag_encr. Wilderness PrDfeosed WI/ erness Areas' Tr.ees Forest Service Acres 33 . 3 0 5 . 8 39 . 1 Visitor days 47. 5 0 5 . 6 53. 1 National Park Service Acres 6 . 7 36. 3 0 Visitor-days 6 . 8 37. 6 0 44. 4 Fish and Wildlife Serv i ce Acres 1 . 7 15 . 8 0 17. 5 Vlsitordays .9 1 . 3 0 2 . 2 Bureau of Land Management Acres 0 0 . 5 .5 Visitor days 0 0 . 3 . 3 Percent of all areas Acres 41. 6 52. 1 6 . 3 100 Visitor days 55. 1 39. 0 5 . 9 100 'Primitive areas include those in the national forests and public lands administered by the Bureau of Land Management. Table 4. Recreational use and miles of trail In National Wilderness Preserve System units (Forest Service and National Par1t Service only), by region (excluding Alaska and Hawaii) . . Visitor-da'f/ • Miles of Trail Reg_ i on [no.(%)] Per Mile of rail Northeast 88 , 300 79 1,117 (0.9) (0.4) Midwest 1,067 , 100 1,835t 582 (1 1.8) (9.5) South 966 , 700 1 , 023 945 (10 .7) (4.6) Rocky Mountai n States 2 , 860 , 200 10, 034 285 (31.6) (52.1) Pacific States 4,067,800 6 , 420 634 (44.9) (33.4) Total 9,050 , 100 19,343 468 (100) (100) 'Most units reported 1978 use data. tlncludes water in the Boundary Water and Canoe Area and portage routes .

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Appendix III. Colorado Conifer Forest Plant Associations -Suitability for Trail location The following plant associations of Colorado conifer forests are grouped in order of resistance to trampling, from highest resistance to lowest resistance. The associations are listed by dominant overstory tree and dominant understory species. Botanic Name 1. DRY GRAMMINOID ASSOCIATIONS Subalpine Abies lasiocarpa-Picea englemanni/ Carex rossii Pinus contorta/carex rossii Pinus aristata/Festuca arizonica Pinus aristata/Festuca thurberi MJntane Pseudotsuga rnenziesii/ Festuca arizonica Pinus ponderosa/carex rossii Pinus ponderosa/Andropogon scoparius Pinus ponderosa/Festuca idahoensis Populus tremuloides/ Ceanothus velutinus 2. DRY SHRUB ASSOCIATIONS Subalpine Abies lasiocarpa-Picea englernannii/ Juniperus carrnunis Pinus contorta/Arctostaphylos uva-ursi Pinus aristata/Ribes rocmtigenum MJntane Pseudotsuga rnenziesii/ Arctostaphylos uva-ursi Pseudotsuga rnenziesii/ Cercx:>carpus m:mtanus Pseudotsuga menziesii/ Holodiscus dumoscus Pseudotsuga rnensiesii/ Symphoricarpos oreophilus P1nus ponderosa-Pinus edulis/ Quercus gambelii Abies concolor-Pseudotsuga menziesii/ Holodiscus durnoscus Carmon Name Subalpine fir-englemann spruce/ ross sedge Lodgepole pine/ross sedge Bristlecone pine/Arizona fescue Bristlecone pine/Thurber fescue Douglas fir/ Arizona fescue Ponderosa pine/ross sedge Ponderosa pine/ Ponderosa pine/Idaho fescue Aspen/ Snowbrush ceanothus Subalpine fir-Englemann spruce/ carm:m juniper Lodgepole pine/kinnikinnick Bristlecone pine/mountain current Douglas fir/ kinnikinnick Douglas fir/ mountain mahogany Douglas fir/ ocean spray Douglas fir/ mountain snowberry Ponderosa pine-Pinyon pine/ gambel oak White fir-Douglas fir/ ocean spray

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3. MJIST GRAMMINOID ASSOCIATIONS Suba.lpine Abies lasiocarpa/Carex geyeri Abies lasiocarpa-Picea englemannii/ Carex geyeri Pinus oontorta/Carex geyeri M::>ntane Picea pungens/poa Picea pungens-Pseudotsuga rnenziesii/ Carex foenea Picea pungens-Pseudotsuga menziesii/ Festuca arizonica Pseudotsuga menziesii/Carex rossii Pseudotsuga menziesii/Carex geyeri Abies ooncolor-Pseudotsuga menziesii/ Festuca arizonica Abies ooncolor-Pseudotsuga menziesii/ sparse Pinus ponderosa/Carex heliophila Pinus ponderosa/Bouteloua gracilis Pinus ponderosa/Carex geyeri Pinus ponderosa/Hesperochloa kingii Pinus ponderosa/Festuca arizonica Populus tremuloides/Carex geyeri Populus tremuloides/Festuca thurberi 4. M:>IST SHRUB ASSOCIATIONS Suba.lpine Abies lasiocarpa-Picea englemannii/ Vaccinium myrtillus Abies lasiocarpa-Picea englemannii/ RIBE Abies lasiocarpa-Picea englemannii/ Erigeron eximius Abies lasiocarpa-Picea englemannii/ Pachistima myrsinites Abies lasiocarpa-Picea englemannii/ Rubus parvif lorus Abies lasiocarpa-Picea englemannii/ Vaccinium scoparium Pinus oontorta/Shepherdia canadensis Pinus oontorta/Vaccinium myrtillus Pinus contorta/Vaccinium scoparium Pinus oontorta/Juniperus communis Picea englemanni/Vaccinium scoparium M::>ntane Pseudotsuga menziesii/Jarnesia americana Pseudotsuga menziesii/ Suba.lpine fir/elk sedge Suba.lpine fir-Englemann spruce/ elk sedge Lodgepole pine/elk sedge Blue spruce/grass Blue spruce-Douglas fir/ foenea sedge Blue spruce-Douglas fir/ Arizona fescue Douglas fir/ross sedge Douglas fir/elk sedge White fir-Douglas fir/ Arizona fescue White fir-Douglas fir/ sparse Ponderosa pine/sun sedge Ponderosa pine/blue gramrna Ponderosa pine/elk sedge Ponderosa pine/spike fescue Ponderosa pine/Arizona fescue Aspen/elk sedge Aspen/'lliurber fescue Suba.lpine fir-englemann spruce/ Rocky M::>untain whortleberry Suba.lpine fir-englemann spruce/ Ribes ssp. Suba.lpine fir-englemann spruce/ fleabane Suba.lpine fir-englernann spruce/ myrtle pachistima Suba.lpine fir-englernann spruce/ thimbleberry Suba.lpine fir-englernann spruce/ whortleberry Lodgepole pine/buffaloberry Lodgepole pine/Ry. Mt. whortelberry Lodgepole pine/whortleberry Lodgepole pine/carm::m juniper Englernann spruce/whortleberry Douglas fir/jamesia Douglas fir/

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Pachistima myrsinites Pseudotsuga rnenziesii/ Physocarpus rronogynus Pseudotsuga menziesii/Acer glabrum Pseudotsuga rnenziesii/ Arctostaphylos patula Pseudotsuga rnenziesii/Quercus gambelii Picea pungens-Pseudotsuga rnenziesii/ Arctostaphylos uva-ursi Abies concolor-Pseudotsuga menziesii/ Arctostaphylos uva-ursi Abies concolor-Pseudotsuga menziesii/ Erigeron ex.imius Abies ooncolor-Pseudotsuga menziesii/ Acer glabnnn Abies concolor-Pseudotsuga menziesii/ Quercus gambelii Abies concolor-Pseudotsuga menziesii/ Vaccinium scoparium Pinus ponderosa/Arctostaphylos patula Pinus ponderosa/Juniperus communis Pinus ponderosa/ Arctostaphylos uva-ursi Populus tremuloides/ Symphoricarpos oreophilus Populus tremuloides/ Amelanchier alnifoliaPrunus virginiana Populus angustifolia/ Amelanchier alnifolia myrtle pachistima Douglas fir/ rrountain ninebark Douglas fir/Ry. Mt. maple Douglas fir/ bearberry Douglas fir/gambel oak Blue spruce-Douglas fir/ kinnikinnick White fir-Douglas fir/ kinnikinnick White fir-Douglas fir/ fleabane White fir-Douglas fir/ Rocky lvbuntain maple White fire-Douglas fir/ gambel oak White fir-Douglas fir/ whortleberry Ponderosa pine/bearberry Ponderosa pine/common juniper Ponderosa pine/ kinnikinnick Aspen/ rrountain snCMberry Aspen/ serviceberr1-chokeberry NarrCMleaf Cottonwood/ serviceberry UNSUITABLE ux:ATIONS -FORB UNDERSTORY ASSOCIATIONS OR WET ASSOCIATIONS Subalpine Pinus flexilis/ Trifolium dasyphyllum Pinus aristata/ Trifolium dasyphyllum Picea englemannii/ Trifolium dasyphyllum Picea englemannii/Equisetum arvense Picea englemannii/rross Abies lasiocarpa-Picea englemannii/ rross Abies lasiocarpa-Picea englemannii/ Li.nnaea borealis Abies lasiocarpa-Picea englemannii/ Calamagrostis canadensis Abies lasiocarpa-Picea englemannii/ Salix glauca Abies lasiocarpa-Picea englemannii/ Senecio triangularis Limber pine/ whiproot clover Bristlecone pine/ whiproot clover Englemann spruce/ whiproot clover Englemann spruce/field horsetail Englemann spruce/rross Subalpine fir-englemann spruce/ rross Subalpine fir-englemann spruce/ twinflCMer Subalpine f ir-englemann spruce/ bluejoint reedgrass Subalpine fir-englemann spruce/ grayleaf willCM Subalpine fir-englemann spruce/ arrCMleaf groundsel

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fvbntane Populus tremuloides/ lathyrus leucanthus Populus tremuloides/ Thalictrum fendleri Populus tremuloides/ calamagrostis rubescens Populus tremuloides/ Ligusticum ssp. Populus tremuloides/ Pteridium aquilinium Picea pungens/ Amelanchier alnifoliaSweida sericea Pinus ponderosa/Quercus gambelii Populus angustifolia-Picea englemannii Amelanchier alnifolia Populus angustifolia-Picea englemannii Lonicera involucrata Populus angustifolia-Picea englernannii Salix exigua-Betula fontinalis Populus sargentii/ Symphoricarpos occidentalis-Elymus cinereus Aspen/ aspen peavine Aspen/ meadCM-rue Aspen/ pinegrass Aspen/ ligusticum species Aspen/ bracken fern Blue spruce/ serviceberry-dogwood Ponderosa pine/gambel oak Cottonwood-Englemann spruce/ serviceberry Cottonwood-Englemann spruce/ Cottonwood-Englemann spruce/ coyote willCM-river birch Plains cottonwood/ snc:Mberry-gian wild rye

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Appendix IV -Scale of Trail Location Suitability 1-t:>st Sui table l. 0% 3% trails on stmni.ts, toeslopes, and valley bottans with Q!Y granrninoid plant associations 2. 0'% 3% trails on smrnits, toeslopes, and valley bottans with Q!y shrub plant associations 3. 3% 6% trails on shoulders and with Q!y granminoid plant associations 4. 3% 6% trails on shoulders and with shrub plant associations 5. 0% 3% trails on smrnits, toeslopes, and valley bottans with moist granminoid plant associations 6. 0% 3% trails on stmni.ts, toeslopes, and valley bottans with moist shrub plant associaticos 7. 3% 6% trails on shoulders and footslq>eS with moist gramninoid plant associations 8. 3% 6% trails on shoulders and footslopes with moist shrub plant associations 9. 6% 9% trails on backslopes grarnninoid plant associations 10. 6% 9% trails on backslopes with 2!Y shrub granmi..noid plant associations ll. 6% 9% trails on backslopes with moist gramninoid plant associations 12. 6% 9% trails on backslq>eS with moist shrub plant associations Least SUi table Field Descriptions ot Scale I.ocations SUITABLE ux:ATIOOS l. & 2. Nearly level, dry meadc7.o1s or open forests with grarrmi.noid or shrub understories Areas most suitable tor trail location are nearly level and dry. Locations are typically on exposed ridges or mesa sumnits, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. These are areas o f lo,..> snow accumulation or where sno,..> blo,..>s off ear 1 y in the spring. The soi 1 s

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here are very well drained with a relatively law rroisture content. '!hey tend to range fran rocky or gravelly soils to coarse loams. To minimize erosion, trails located in these areas should not exceed 3%. 3. & 4. Gently sloping, dry meadows or open forests with granminoid or shrub understories '!he second roost sui table areas for trail location have very gentle slopes and are dry. I..cx:ations are typically on exposed ridge and mesa surnnits or shoulders, scree or rocky slopes, or raised benches; and tend to have a southerly to westerly aspect. 'lbese are areas of low snow accumulation or where SilCM blows oft early in the spring. '!he soils here are very well drained with a relatively law rroisture content. '!bey tend to range fran rocky or gravelly soils to coarse loams. 'Ib mi.ni.rnize erosion, trails located in these areas should not exceed 6%. 5. & 6. Nearly level, rroist meadows or forests with granminoid or shrub understories 'lhe third roost suitable locations tor trails are nearly level and relatively moist. 'lbese may be protected ridge surnni ts, toes lopes or valley bot tans. Typical locations my be streamsides, lake margins, draws, benches, or meadows. Also included are areas protected fran extreme sun or wind. Aspect may be northerly to easterly, especially where little snow acctmn.llates; or southerly to sout:hiNesterly where snow tends to accumulate. Soils are well drained and tend to range tran gravelly and sandy loams to sandy clays. To minimize erosion in these areas, trail slopes should not exceed 3%.

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7. & 8. Gently sloping, ITDist meadCJ.Ys or forests with granminoid or shrub understories '!he tourth suitable trail locations for trails are gently sloping and relatively 'Ihese may be protected ridge sunmits or shoulders, or footslq>es. Typical locatioos may be streams ides, draws, benches, or rneadCJ.Ys. Also included are areas protected fran extrare sun or wind. Aspect may be northerly to easterly, expecially where little snCJ.Y accumulates, or southerly to southwesterly where snCJwY tends to accumulate. Soils are well drained and tend to range fran gravelly and sandy loams to sandy clays. To minimize erosion in these areas, trail slq>es should not exceed 6%. 9. & 10. Sloping, dry meadcws or open torests with granminoid or shrub understories. 'Ihe titth best locations tor trails are IOOderately sloping and dry. 'Ibese are backslopes and draws. Typical locations may be exposed or windswept slopes and may tend to have a southerly to westerly aspect. 'Ihese are areas of lCJ.Y snCJ.Y accumulation or where snCJwY blCJ.Ys off early in the spring. 'Ihe soils here are very well drained with a relatively lCJ.Y ITDisture content. 'Ihey tend to range fran rocky or gravelly to coarse loams. To mini.mize erosion, trails located in these areas should not exceed 12%. 11. & 12. Sloping, IOOist mead<.Jvls or open forests with gramninoid or shrub understories The sixth most suitable locations for trails are IOOderately sloping and moist. 'Ihese are backslopes and draws. Typical loactions may be northerly or easterly

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slq>es and draws where little sna.v accumulates, or southerly to westerly slopes and draws where sna.v tends to accumulate. 'ltlese are areas protected fran extreme wind descication. Soils are well drained and tend to range fran rocky and coarse loams to finer loams. To minimize erosion, trails located in these areas should not exceed 12%. UNSUITABLE ux::ATIONS FOR TRAilS A. Steep trail grades and exterxied slope lengths Steep slq>es or terrain which requires trail slq>es to exceed 12% for prolonged stretches are unsuitable due to excessive soil erosion. Erosion increases w ith both grade and slq>e length. CAl trails of 12% slq>e and steeper, maintained for 100', erosion increases dramatically. Trails may be located .5?!2 slopes which are greater than 12%, but the slq>e of the trail should not exceed 12%. B. Wet sites Wet sites are unsuitable due to the extremely la.v resistance of the soil and vegetation to trarrpling. Trarrpling on a saturated soil canpacts it and destroys its structure. 'Ibis diminishes the soil's resistance to erosion as well as decreases ease ot root penetration. In addition, plants in saturated conditions tend to have a high water content in their tissues, and thus are very likely to be broken upon trarrpling.

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C. Forb-daninated understories Forb understories are unsuitable due to the lc::M trampling resistance of the vegetative form of many torbs. Many forbs have single stems with leaves arising fran the stem. 'Ibis form has been noted to be the least resistant to trampling.

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BIBLicx;RAPHY 1. Hendee, John C. ; Stankey, George H. ; Lucas, Robert C. . Wilderness Management. U.S.D.A. Forest Service, Pub. No. 1365; 1978. A basic text, the "bible", on history, managment phioosophy, and issues relating both to the land and the user. 2. Heirnichs, J.; "Wilderness-Can We Have It and Use It Too?"; Amer. For.: 16-53; 1980. Range of impacts and management challenges in wild lands. 3. Cole, D. N.; "Assessing and Monitoring Backcountry Trail Conditions"; Res. Pap. INT-303. Ogden, UT: U.S.D.A. Forest Service, Intenrountain Forest and Range Experiment Station; 1983. Approaches to measuring trail conditions, as applied to the Selway-Bitterroot Wilderness in Montana. 4. Weintraub, A.; Adams, R.; Yellin, L.; "Land Management Planning: A Method of Evaluating Alternatives". Res. Pap. PSW-167. Berkeley, CA: U.S.D.A. Forest Service, Pacific Southwest Forest and Range Experiment Station, 1982. Alternatives in use distribution among campsites 5. Liddle, M. J.; "A Selective Review of the Ecological Effects of Human Trampling on Natural Ecosystems"; Biol. Conserv. (7): 17-33; 1975. British. Impacts of trampling, and management actions to treat impacts. 6. Dale, D.; Wever, T.; "Trampling Effects on Vegetation of the Trail Corridor of Northern Rocky Mountain Forests" • Ecology (?) • Impacts to trails, species composition, and frequency of species. 7. Cole, D. N. ; "Estimating the Susceptibility of Wildland Vegetation to Trailside Alteration"; J. App. Ecol., vol. 15; 1978. Changes in species composition, cover, and resistance to trampling along trails in Eagle cap Wilderness. 8 . Cole, D. N. ; and B. Ranz ; "Temporary campsite Closeure in the Selway-Bitterroot Wilderness", J. For., vol. 81; 1983.

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Reasons for closure of lakeside campsites and resultant shifts in use patterns. 9. Cole, D. N.; and R. K. Fichter; "Campsite Impact on Three Western Wilderness Areas" ; Environ. Man. , vol. 7, no. 3 ; 19 8 3 . Relationship between frequency of use and amount of impact on campsites in Montana and Oregon. 10. Cole, D. N.; and J. Benedict; "Wilderness Campsite Selection What Should Users Be Told?"; Park Science 3(4): 5-l; 1983. Impacts, conditions of campsites and visitor education. Standard classification of campsite condition and recommended frequency of use. 11. Clark, R. N.; and K. B. Do.Yning; "Why Here and Not There: Conc;1itioning Nature of Recreation Choice", In: Proceedings Syrrq;x:>siurn on Recreation Choice Behavior; Missoula, Ml',3/22-23/84. Factors relating to users' for selection of recreation area. 12. Lucas, R. ; Wilderness Management Research Project Leader, U.S. F. S. , Intenrountain Forest and Range Experiment Station, Missoula, Ml'; phone conversation, Oct. 9, 1985. Discussion on my thesis approach and relevant research. He co-authored the "bible" -see 1. He liked my approach and didn't knCM of a similar research effort. 13. Vallejos, R.; Assistant Recreation Forester, U.S.F.S., Mount Evans Wilderness Area, CO; phone conversation, Oct. 21, 1985. Discussion of history of existing trail locations, user demographics, relationship of adjacent roads to access. 14. Clawson, M.; and B. Held; The Federal lands -Their Use and Management; Johns Hopkins Press, Baltimore, MD; 1957. Ma.nagment history of federal lands. 15. Brubaker, s.; ed. Rethinking the Federal lands; Johns Hopkins Press, Wash, D.C.; 1984. History of management policies of federal agencies.

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16. caldwell, L. K.; "An Ecosystems Approach to Public land Policy"; In: Western Resources Conference, lOth, Colo. State Univ.; 1968. Philosophy concerning need to modify existing, historic approach of viewing land development and management toward wholistic, ecological approach. 17. Robinson, G. 0.; The Forest Service, A Study in Public land Management; Johns Hopkins Pres, Baltimore, MD; 1975. Management prooeedures and policies of the Forest Service, sustained-yield/multiple use concept. 19. Schechter, M.; and R. C. Lucas; "Simulation of Recreational Use for Park and Wilderness Management"; Johns Hopkins Press, Baltimore, MD; 1978. Discussion on the use and validity of a computer simulator for assessing user encounters, and different management options, on trails. 20. Brockman, C. F.; and L. C. Merriam, Jr.; Recreational Use of Wild Lands; McGraw-Hill; 1979. Management philosophy and objectives for recreation on undeveloped lands. 21. Lucas, R. C.; "Visitor Characteristics, Attitudes, and Use Patterns in the Bob Marshall Wilderness Ccrnplex, 1970-82."; U.S.D.A. Forest Service, Interrrountain Research Station, Ogden, UT; 1985. Relationships of camping practices, party size, and i.rrpact by hikers, horse packers, and outfitters. 22. Cole, D. N.; "campsite Conditions in the Bob Marshall Wilderness, MJntana"; U.S.D.A. Forest Service, Interrrountain Forest and Range Experiment Station, Ogden, UT; 1983. Relationship of site moisture and vegetation form to campsite conditions. 23. Daubenmire, R. F.; Plants and Envirornnent, a Textbook of Autecology; John Wiley and Sons, Inc., New York, NY; 1974. How habitat factors affect individual plants. 24. Daubenmire, R. F.; Plant Ccmnunities, A Textbook of Plant Synecology; Harper and Row, New York, NY; 1968. How plants relate to each other and function in ccmnuni ties.

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25. Johnston, B. C.; Plant Associations (Habitat 'I'ypes) of Region 'IWo; U.S.D.A. Forest Service, Rocky r.buntain Region; Lakewood, CO, 1984. Description of plant associations found in Colorado, New Wyaning, Kansas, and Nebraska. 26. Johnston, B. C.; Key to the Forested Plant Associations of Northern Colorado and Southern Wyaning; U.S.D.A. Forest Service, Rocky r.buntain Region; Lakewood, CO; 1985. Key to identifying and summary of site conditions of forests o f that area. 27. Brady, N. C.; The Nature and Property of Soils; MacMillan Publishing Co., Inc., New York, NY; 1974. Textbook of soil properties. 28. Baver, L. D.; W. H. Gardner; w. R. Gardner; Soil Physics; John Wiley and Sons, Inc., New York, NY; 1972. Textbook of physical properties of soils in engineering and agricultural awlications. 29. Barbour, M. G.; J. H. Burk; W. D. Pitts; Terrestrial Plant Ecology; Benjamin CUmmings Publishing Co., Inc.; 1980. Textbook of plant ecology. 30. Cronquist, A.; A. H. Holm9Ten; N. H. Holm9Ten; J. L. Reveal; R. K. Holm9Ten; Inte:mountain Flora, Vascular Plants of the Inte:mountain _____ W_e_st_; Columbia University Press, New York, NY; 1977. Key of vascular plants of the Intennountain West. 31. Willard, B. E.; J. Marr; "Effects of Hurrian Trampling on Tundra in Rocky fuuntain National Park"; Biol. Conserv.; 1970. Susceptibility of various tundra communities to trampling damage. 32. Harrington, _; Plants of Colorado Key of all plants found in Colorado. 33. Cole, D. N.; and E. G. S. Schreiner, canpilers; "Impacts of Backcountry Recreation: Site Management and Rehabilitation -An Annotated Bibliography"; U.S.D.A. Forest Service General Technical Report INT-121; Inte:mountain Forest and Range Experiment Station, O:Jden, UT; 1981.

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Collection of summaries of research. 34. Dunne, T.; and L. B. Leopold; Water in Environmental Planning; W. H. Freerran and CCinpany, San Francisco; 1978. The role of water in environmental planning. 35. Hooper, Lennon; NPS Trail Managenent Hand}:xx)k; U.S.D.I., National Park Service, Denver Service Center. Guide to locate and build trails. 36. U.S. F. S. ; Trails Management Hand}:xx)k; U.S. D .A. Forest Service. Guide to locate and build trails. 37. Proudman, Bobert D.; AM: Field Guide to Trail Building and Maintenance; Applachian 1-buntain Club; 1981. Guide to locate and build trails. 38. Ruhe, Robert; Gearorphology; Houghton Mifflin Co.; Boston; 1975. Geology and landform. 39. U.S.F.S.; Recreation Cflportunity Spectrum; U.S.D.A. Forest Service. Discussion of appropriate development levels and types of use of trails in various settings. 40. U.S. F. S. ; land and Resource Management Plan, Shoshone National Forest; U.S.D.A. Forest Service, Cody, WY; 1985. Management objectives, directions and standards. 41. Carr, Lee; Wilderness Recreation Forester; U.S. F. S. , Rocky 1-buntain Regional Office, lakewood, CO; numerous personal conversations, Oct. -Apr., 1986. Numerous conversations concerning wilderness trails and this thesis. 42. Trenholme, Richard; Soils Specialist, Interrrountain Soils; Denver, CO; phone conversations, March -April, 1986.

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' Discussions on Colorado geomorphology and soils. 43. Soil Conservation Service; National Soils Handbook; U.S.D.A. S.C.S.; May 1983. Proceedures for performing surveys and tests on soils.