C04-3 FS-1262 Trail Maintenance Notebook.pdf

PDF 17 MB Posted Aug 10, 2026

Attached to: Grounds Maintenance Services – Guayama Research Station Federal contract opportunity
Solicitation number: 1240BE26Q0099
Issued by: Department of Agriculture Forest Service International Institute of Tropical Forestry Jardin Botanico Sur

About this file

Written by GovTribe AI · Aug 10, 2026

This is a Request for Quotation (RFQ) for grounds maintenance services at the Guayama Research Station, a U.S. Department of Agriculture Forest Service facility located in Puerto Rico on the south side of the island where the Guayama, Cayey, and Salinas municipalities meet. The solicitation number is 1240BE26Q0099, and this acquisition is a Total Small Business Set-Aside with a North American Industry Classification Standard Code of 561730 and a small business size standard of $9.5 million. The contractor shall provide comprehensive grounds maintenance services including routine landscaping, vegetation control, roof maintenance, pressure washing of exterior surfaces and roofs, and housekeeping services to ensure safety, functionality, and aesthetic quality of all outdoor areas, roofs, and designated surfaces in compliance with applicable federal, state, and local regulations and industry best practices.

The Guayama Research Area encompasses steep topography with diverse vegetation and is traversed by Quebrada del Palo, which runs from east to west across the property with several intermittent streams feeding into it. The contractor must plan, program, administer, manage, and execute all work necessary to maintain the facility in a clean, safe condition for staff and visitors. The statement of work establishes the scope, standards, and responsibilities for performance, with specific requirements addressing the unique environmental conditions and maintenance challenges presented by the property's terrain and hydrological features.

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Other files for this federal contract opportunity

Other files attached to Grounds Maintenance Services – Guayama Research Station, newest first.
File	Type	Posted
Z08 Vendor Question and Answers by Email.pdf	PDF	Aug 21, 2026
C04-1 1240BE26Q0099 schedule of items and work statement rev 1.pdf	PDF	Aug 21, 2026
1240BE26Q0099 amendment 0003 PWS updated.pdf	PDF	Aug 21, 2026
Z07 Question and Answers from Site Visit 08192026.pdf	PDF	Aug 21, 2026
C04-5 Guayama Research Station map and grounds information.pdf	PDF	Aug 14, 2026
1240BE26Q0099 amendment 0002 Guayama Research Station map and grounds information.pdf	PDF	Aug 14, 2026
1240BE26Q0099 amendment 0001 wage rate correction.pdf	PDF	Aug 11, 2026
C04-2 wage rates Guayama.pdf	PDF	Aug 11, 2026
C04-2 Wage Rates.pdf	PDF	Aug 10, 2026
C04-1 1240BE26Q0099 schedule of items and work statement.pdf	PDF	Aug 10, 2026
C04-4 STD_912-02_Clearing_Limits_Brushing.pdf	PDF	Aug 10, 2026

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Trail Maintenance and Construction Notebook

FS-1262 | February 2025 iii

This publication was produced in cooperation with the Recreational Trails Program of the Federal Highway Administration, U.S. Department of Transportation.

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of this document.

The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official policy of the U.S. Department of Transportation. This report does not constitute a standard, specification, or regulation.

Non-Binding Contents

Except for the statutes and regulations cited, the contents of this document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide information and clarity to the public regarding existing requirements under the law or agency policies.

The Forest Service, an agency of the U.S. Department of Agriculture, has developed this information for the guidance of its employees, volunteers, partners, contractors, and cooperating Federal and State agencies, and is not responsible for the interpretation or use of this information by anyone except its own employees. The use of trade, firm, or corporation names in this publication are for the information and convenience of the reader and does not constitute an endorsement by the Department of any product or service to the exclusion of others that may be suitable.

In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs).

Remedies and complaint filing deadlines vary by program or incident. Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the State or local Agency that administers the program or contact USDA through the Telecommunications Relay Service at 711 (voice and TTY). Additionally, program information may be made available in languages other than English.

To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at How to File a Program Discrimination Complaint and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632-9992. Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Mail Stop 9410, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: program.

intake@usda.gov.

USDA is an equal opportunity provider, employer, and lender.

https://www.usda.gov/oascr/how-to-file-a-program-discrimination-complaint mailto:program.intake@usda.gov mailto:program.intake@usda.gov v

Trail Maintenance and Construction Notebook 2025 Edition

Meckenzie Helmandollar-Powell, Project Manager, Washington Office Trail Program, USDA Forest Service

Scott Johnson, Contributor and Co-Project Manager, Washington Office Trail Program, USDA Forest Service

Garrett Villanueva, Travel Management Program Manager, Washington Office, USDA Forest Service

Kerry Wood, Trail Program Manager, Southwestern Region Office, USDA Forest Service

Jess May, Assistant Recreation Officer, Mt. Whitney Ranger District, Inyo National Forest, USDA Forest Service

Mike Gabor, Forest Engineer, Lake Tahoe Basin Management Unit, USDA Forest Service vi

Contents

1. Introduction

2025 Edition�� 2 Before Starting Work �� 5

Sample Project Planning Checklist �� 6 Applicable Laws ��7 Working With Partners and Volunteers �� 9 Safety��10

Project Risk Assessment and Safety Briefing ��10 Safety Equipment �� 12

Project Prioritization�� 14

2. Basic Trail Concepts Sustainability �� 16

Physical Sustainability �� 18 Water Flow�� 21 Soil ��25 Trail Use Impacts �� 31

Management Objectives��33 Recreation Opportunity Spectrum�� 36 Trail Types �� 37 Trail Development Classes��38

Accessibility �� 41 Location��44

Trail Grade �� 47 Slope Ratio��48 Fall Line ��49 The Half Rule ��52 Rolling Contour Trails ��53 vii

3. Maintenance Trail Assessments �� 57 Maintenance Plans �� 60 Sign and Marker Maintenance �� 61 Corridor Maintenance�� 63

Corridor Clearing Dimensions��65 Sawyer Certification��67 Brushing ��67 Limbing ��70 Bucking�� 73 Tree Felling�� 78

Tread Maintenance�� 80 Reestablish Tread and Stop Creep �� 81 Reestablish Outsloping ��83 Maintain Drainage ��85 Address Trail Widening �� 87 Other Maintenance Solutions ��89

Objects in the Trail Corridor�� 94 Rock Removal �� 94 Root and Stump Removal ��97

4. Structures Draining Water ��100

Solutions for Draining Water Off Existing Trails �� 101 Rolling Grade Dips ��102 Use Topography To Force Uphill Undulation ��106 Knicks �� 108 Waterbars �� 110

Areas With Saturated Soil�� 112 Rock Underdrains��114 viii

Causeways �� 116 Crossing Streams and Rivers��120

Shallow Stream Fords��120 Culverts�� 124 Trail Bridges�� 131

Steep Trail Grades and Hillside Slopes ��141 Turns in Steep Terrain��141 Climbing Turns �� 143 Switchbacks�� 146 Radius Switchback�� 151 Retaining Structures�� 153 Rock Retaining Walls��154 Log Crib Walls�� 161 Wire Basket Retaining Walls �� 168 Steps �� 169 Armoring the Tread�� 179

5. Signs Placement �� 187 Posts ��188 Designed for Accessibility �� 192 Reassurance Markers�� 192

Blazes �� 193 Flexible Fiberglass Markers�� 196 Cairns�� 197

National Trails�� 199

6. Construction and Decommissioning Relocation��203 Preparing for Construction ��206

New Trail Planning��206 ix

Plotting the Proposed Trail on a Map ��209 Using a Clinometer�� 212 Scouting the Route�� 215 Layout�� 219 Flagging��220

Tread Construction��224 Sample Preconstruction Checklist��225 Best Practices for Construction ��226 Full-Bench Construction��232 Partial-Bench Construction ��234 Backslope��236 Hand-Built��240 Machine-Built ��243

Decommissioning��244 Planning for Success��245 Steps To Decommission or Obliterate a Trail��246

Check Dams �� 250

7. Tools and Equipment Tool Safety��255 Brushing�� 257 Chopping ��258 Digging and Tamping��260 Grubbing�� 261 Lifting and Hauling ��265 Measuring ��268 Mechanized Trail Building Equipment �� 270 Peeling and Shaping�� 273 Pounding and Hammering��274 Rock Work�� 275 x

Sharpening ��278 Sawing�� 281

8. Resources Forest Service Trail and Trail Bridge Policy��286 Websites and Publications ��288

Accessibility ��288 Blasting and Rock Breaking��288 Condition Assessments ��289 Construction Prework ��289 Corridor Maintenance��289 Decommissioning��290 Design��290 Laws (others not cited here also apply)��292 Maintenance Solutions��293 Trail Bridges and Other Saturated Areas��293 Safety ��294 Signs��294 Sustainability Practices ��295 Tools ��295 Training��298 Working With Partners and Volunteers��298

Library Card��299 Common Conversions and Comparisons �� 301 Sample Day Pack List ��302 Sample Medical Incident Report��303 Tailgate Safety Session��306 After-Action Review �� Back Cover xi

TRO

D U

TIO

The U.S. Department of Agriculture (USDA), Forest Service manages the largest trail network in the world, with over 164,000 miles of trails. Continued access to these well-loved and much-needed trails depends on the shared stewardship of agency employees, Tribes, partners, volunteers, contractors, permit holders, communities, and everyone who loves trails.

This notebook is a practical reference for trail maintenance and construction written in an easy-to-understand fashion, with a focus on sustainable natural surface trails. It is not a policy document, and it doesn’t cover everything a trail professional needs to know. After reading this notebook, the authors encourage you to learn more and seek knowledge from other people and resources. Attend a trail skills training, invite a trail professional from another area, or explore the documents and websites listed in the “Resources” chapter of this notebook.

Most importantly: get out there, be safe, and do good work.

2025 Edition This notebook replaces the 2007 version of the “Trail Construction and Maintenance Notebook.” The new title reflects where trail workers spend most of their time and resources—maintaining trails. This edition highlights the skill and experience it takes to construct and maintain trails,

1. INTRODUCTION

emphasizes collaborative trail planning, and underscores constructing trails with long-term maintenance in mind.

The notebook features eight chapters: 1. Introduction, 2.

Basic Trail Concepts, 3. Maintenance, 4. Structures, 5.

Signs, 6. Construction and Decommissioning, 7. Tools and Equipment, and 8. Resources. The “Maintenance” chapter describes general maintenance practices. Refer to the “Structures” chapter for maintenance tips about specific structures. The “Tread Construction” section in chapter 6 describes building new trail. The “Resources” chapter provides references and web addresses separated by topic.

Welcome to the trail community! The authors hope this notebook helps you care for the trails you love.

This notebook also draws on a few new resources.

High-resolution photos. Updated photos. Visit the online glossary on the trail terms web page to download high-resolution color photos.

Diagrams and 3D models. Diagrams based on engineer-approved Forest Service standard trail drawings. These are teaching aids and shouldn’t be used for construction specifications. Some diagrams are also available as 3D models that can be viewed online (fig. 1-1). Visit the Forest Service Plans for Trail and Trail Bridge Structures web page or scan the QR code to access the 3D models and the full list of engineer-approved Forest Service standard drawings of trail and trail bridge structures.

https://www.fs.usda.gov/managing-land/trails/trail-management-tools/terms https://www.fs.usda.gov/managing-land/trails/trail-management-tools/trailplans

Figure 1-1. Some diagrams have a 3D model available; scan the QR code to access these models. More detailed diagrams of some structures and other resources are on the Plans for Trail and Trail Bridge Structures web page.

This version of the notebook promotes understanding and problem-solving. Understanding why things are done a certain way is as important as doing them a certain way. If you know why something is happening, you’ll figure out how to solve the problem. Soak up the core concepts. Be curious and don’t be afraid to fail. Experiment and keep track of the results. Add new techniques and tactics to your bag of tricks. Get dirty and HAVE FUN!

Readers are encouraged to consult Forest Service directives and the trail program website. A companion publication to this notebook, “Trail Structures for Wet, Unstable, and Sensitive Areas,” provides an overview of techniques for building and maintaining trails in saturated soils. These publications are available on the Forest Service’s national publications page.

Before Starting Work Before starting any new trail project, consider how the project fits with current priorities and line officer support.

Project planning should include the scope of the project, how to determine if it’s successful, what environmental approvals you’ll need, needed resources, and the timeline for completion.

In the Forest Service, a “line officer” is someone with decision-making authority delegated from the

Chief. Local trail managers typically work with district rangers, who are line officers.

https://www.fs.usda.gov/about-agency/regulations-policies/national-directives https://www.fs.usda.gov/about-agency/regulations-policies/national-directives https://www.fs.usda.gov/managing-land/trails https://www.fs.usda.gov/about-agency/publications https://www.fs.usda.gov/about-agency/publications

Sample Project Planning Checklist

□ �Consider environmental, social, and economic sustainability in trail planning. Refer to chapter 2.

□ �Does the proposed route support current priorities for the trail program and align with applicable land management plans (forest plan, wilderness management plan, etc.)?

□ �Will the proposed alignment be physically sustainable considering local soils, hydrology, and terrain? Will it affect historic sites or sensitive habitat?

□ �How does the proposed route fit into the landscape and larger trail system, which may include nearby trails managed by other entities?

□ �Does the proposed route satisfy a need for multiple user groups? Consider seeking public input and community engagement on project ideas and engaging nontraditional groups for new perspectives and to attract new trail visitors and potential new trail stewards.

□ �How will the new construction and long-term maintenance be funded? Are grants and other funding sources reliable?

□ �Considering the current workload, can the current or future arrangement of employees, partners, and volunteers conduct annual maintenance on the proposed route?

All trails aren’t perfect for all locations. Just because a location appears perfect for a trail doesn’t mean a trail is appropriate in that location (i.e., there may be unseen cultural and natural resources). Involve line officers and environmental and cultural specialists before starting work.

Every action that Federal employees, partners, and volunteers take is guided by laws and policies. Before starting work, consider the impacts to the environment and compliance with any Federal, State, and local laws and policies.

Applicable Laws The National Environmental Policy Act (NEPA) requires Federal agencies to assess the environmental impacts of every action they take and disclose the decision-making process to the public. Forest Service procedures for implementing NEPA are in Title 36 of the Code of Federal Regulations (CFR) Part 220. Line officers must approve and sign an environmental study document for some activities, such as decommissioning routes and constructing new trail. The NEPA “decision document” usually describes how, where, and when work will occur and any required mitigation measures. The local line officer may decide that some actions are excluded from documentation in an environmental assessment or environmental impact statement because they don’t significantly impact the environment (categories of action excluded from environmental documentation, a.k.a. “categorical https://www.ecfr.gov/current/title-36/chapter-II/part-220?toc=1 https://www.ecfr.gov/current/title-36/chapter-II/part-220?toc=1 exclusions” are listed in FSH 1905.15, Section 32 – National Environmental Policy Handbook).

The following activities typically don’t require a NEPA decision document or project file:

• Grading, cleaning, and maintaining drainage features.

• Grubbing, brushing, and removing downed trees.

• Repairing or replacing existing structures, including steps, retaining walls, puncheons, or bog bridges.

• Installing or replacing reassurance markers or informational signs (e.g., along a trail or at trail junctions, at trailheads and parking areas, or at overnight sites or bridges).

• Resurfacing to original condition, including native material cleanup, gravel replacement, or repaving.

A list of common trail maintenance and construction activities and associated required environmental analysis is available on the Trail Best Practices page of the National Trail Program SharePoint site (Forest Service internal link).

Conditions and resource needs vary, so consult the line officer or trail manager before starting work.

In addition to NEPA, other laws and regulations may apply such as the Clean Water Act, National Historic Preservation Act, Endangered Species Act, National Trail System Act, the Forest Service’s Travel Management Rule. Working near water also requires special considerations to prevent disturbing sensitive riparian areas or adding sediment to the water source (a riparian area is the zone between the water body and dry land).

https://www.fs.usda.gov/about-agency/regulations-policies/handbook/190915-30-categorical-exclusion-documentation https://www.fs.usda.gov/about-agency/regulations-policies/handbook/190915-30-categorical-exclusion-documentation https://usdagcc.sharepoint.com/sites/fs-nfs-ntprg/ https://usdagcc.sharepoint.com/sites/fs-nfs-ntprg/

During trail maintenance and construction, the local trail manager must comply with all applicable laws and regulations and any mitigation measures described in the associated NEPA decision document.

Working With Partners and Volunteers In many districts, partners (a.k.a. collaborators) and volunteers contribute substantially to trail work. Engaging partners and volunteers increases the capacity of trail managers to accomplish trail work and promotes public land stewardship. While some trail work requires years of hands-on experience and mentoring, other opportunities— some that don’t require swinging tools or carrying heavy packs—engage people of any skill level and interest. The Forest Service invites people of all abilities to assist with gathering trail information, conducting trail inspections, sponsoring trainings, coordinating an event or project, or other less-physical tasks. Whatever task is assigned, partners and volunteers working on trails ideally have the experience or training in the type of trail work being done and the tools being used, are able to follow safe practices, and have approval of the agency trail manager.

Partners and volunteers working on National Forest System lands also need a written agreement signed by the local line officer. Partners typically work under a mutual benefit agreement. Individual and group volunteers work under a volunteer agreement, which provides workers’ compensation, tort liability coverage, and coverage for personal property damage or loss. Visit the Forest Service’s Partnership Resource Center website for more details.

Partners and volunteers can only work under formal agreement and authorization from the Forest Service.

Working independently might cause irreparable cultural or natural resource damage, lessen future recreation access for everyone, and have legal ramifications.

Safety Personal safety is paramount in trail work. Safe workers demonstrate use of necessary personal protective equipment (PPE), adhere to site and environmental safety precautions, maintain situational awareness, and know what to do in an emergency. Seasoned trail workers will tell you, “nothing we do today is worth being injured for” and “safety is everyone’s priority.” Consult the Health and Safety Code Handbook (FSH 6709.11). Chapter 20, “Work Projects and Activities,” and chapter 50, “Employee Safety, Security, and Health” are particularly important.

Project Risk Assessment and Safety Briefing Each project or task requires preparing a risk assessment.

Three methods are common in the Forest Service: the risk assessment code (RAC) matrix, job hazard analysis (JHA), and green-amber-red (GAR) assessment tool (FSM 6710). Trail managers and work leaders are responsible for https://www.fs.usda.gov/working-with-us/partnerships https://www.fs.usda.gov/about-agency/regulations-policies/national-directives https://www.fs.usda.gov/about-agency/regulations-policies/manual/6710-safety-and-occupational-health-program-administration https://www.fs.usda.gov/about-agency/regulations-policies/manual/6710-safety-and-occupational-health-program-administration conducting or delegating a project risk assessment. The local line officer must approve the risk assessment for the particular task on an annual basis.

Review and discuss the risk assessment document with everyone working on the project before the work begins, when changing work sites, or if conditions change. The discussion should be documented in a tailgate safety form (FSH 6719.8 – Exhibit 06) and include:

• Itinerary (planned route of travel, destination, estimated time of departure/arrival)

• Names of crew members

• Forecasted weather conditions

• Work hazards and abatement actions (including working with specialized equipment and environmental hazards, such as lightning)

• Communication plan (check-in/check-out procedures and crew communication)

• Emergency evacuation plan (refer to the example medical incident report in chapter 8)

It is good practice to hold an after-action review (AAR) at the end of every shift. Example AAR discussion questions are on the back cover of this notebook.

https://www.fs.usda.gov/libraries/pdf.js/web/viewer.html?file=https://www.fs.usda.gov/sites/default/files/2024-03/wo-6700-2016-1-10.pdf

Safety Equipment A minimum set of PPE is required for all trail work (FSH 6709.11, chapter 70):

• Forest Service-approved hardhat or helmet that meets the American National Standards Institute standards (ANSI Z89.1). The line officer can also approve hardhats or helmets that are demonstrated to be at least as effective as the approved head protection.

• Eye protection with side protection that meets ANSI Z871.1 for any type of sawing or rock work.

• Long pants and long-sleeved shirts for most situations to protect from cuts and scrapes, insects, and sunburn.

Short-sleeved shirts may be used based on the risk assessment.

• Gloves that protect against severe cuts, abrasions, and punctures.

• Footwear with nonskid outsoles that provide ankle support.

• Other task-dependent safety items:

o �Hearing protection when working near power equipment (louder than a vacuum cleaner or greater than 85 dB).

o �Dust masks for some types of rock work and in extremely dusty conditions.

o �Cut-resistant or leather laced boots when using a chainsaw or crosscut saw.

https://www.fs.usda.gov/about-agency/regulations-policies/handbook/670911-70-personal-protective-equipment-glossary-and https://www.fs.usda.gov/about-agency/regulations-policies/handbook/670911-70-personal-protective-equipment-glossary-and o �Chaps or cut-resistant leg protection when using a chainsaw or crosscut saw that meets the requirements of Forest Service 6170-4 or ASTM F-1897 (current version). Chaps must overlap boots at least 2 inches.

Other essential items

• Personal items such as foul-weather layers, hat, water, snacks, sunscreen, sunglasses, insect repellent, lip moisturizer, headlamp or flashlight with batteries, and personal medications.

• Communication devices such as a radio, cell phone, personal locating beacon—or all three.

• First aid kit that includes standard first aid supplies and bloodborne pathogen protective equipment (rubber gloves, face masks, eye protection, and CPR clear-mouth barriers).

• Mission-essential gear (not necessarily safety related but will make you more effective) such as trail tools, clinometer, map, compass, GPS unit, flagging, tape measure, notepad, pen, permanent marker, and this notebook.

Don’t start the job unless you are properly equipped!

Now that you have authorization and you and your crew are trained and properly equipped, how do you decide where to start?

Project Prioritization Often the amount of trail work exceeds the capacity of people or time available to do it. Setting priorities ensures that the most critical and impactful work gets done first.

Give priority to maintenance work on popular trails that are creating unsafe conditions, and then address erosion or other impacts on approved or user-created routes that are damaging adjacent natural or cultural resources.

Forest Service policy does not allow improvements or maintenance to unauthorized user-created routes.

Consider the existing maintenance backlog and long-term maintenance needs before adding new trails and when accepting new trail proposals from the public or partners.

The national quality standards for trails (FSH 2309.18 chapter 10) and the trail management objective (TMO) for each trail will help you identify departures from the standards and what maintenance is needed. Refer to the “Management Objectives” section in chapter 2 of this notebook for more information about national quality standards and TMOs.

Also consider the level of use, trail development class, public safety, resource protection, and crew capacity when setting priorities for trail maintenance. Accomplishing small, specific tasks in the proper manner can be more impactful than completing a lot of marginal-quality work.

https://www.fs.usda.gov/about-agency/regulations-policies/handbook/230918-10-trail-planning

SIC

TRA

IL C

O N

EPTS

Trail management in the Forest Service means building and maintaining trails that support the agency’s mission. Familiarity with a few basic trail concepts helps trail managers think critically about and make decisions regarding trails and trail systems. These basic concepts also give trail managers a common language that describes trails across the system.

Sustainability Trail sustainability is based on three overlapping concepts:

environmental, social, and economic sustainability. All three are important to identify a fully sustainable trail, both individually and as part of the trail network. A sustainable trail is planned, designed, constructed, managed, and maintained in a way that doesn’t negatively impact the adjacent natural and cultural resources, meets trail visitor expectations, and is affordable, now and into the future. Sustainable trail construction and maintenance reduces long-term costs, while still delivering high-quality experiences to the public.

2. BASIC TRAIL CONCEPTS

Environmental sustainability. Avoids or minimizes impacts to natural and cultural resources. The trail tread and infrastructure can physically withstand the expected effects of human and natural forces.

Social sustainability. Trail users and the community like the trail, use it, and support it.

Economic sustainability. Trained workers and sufficient funds are available to construct, maintain, and repair the trail.

Many National Forest System trails, as well as many user-created routes, are not sustainable in their current alignment (fig. 2-1). Many of these trails, often called “legacy trails,” were once game trails, paths between villages and hunting grounds, or routes to access minerals and timber and were not designed or constructed with sustainable principles in mind. Legacy trails suffer from overly steep grades, poor alignment on the landscape, and are difficult to manage. They can also be causing substantial soil loss and trail widening that can lead to damage to natural and cultural resources, poor user experiences, and increasing maintenance frequency and costs. Some may have been incorporated into the forest transportation system as official routes without environmental studies and, in many cases, are not being used for their intended purpose.

Trail managers continue to deal with legacy trails for a variety of reasons—lack of staff to complete an environmental evaluation, lack of resources to accomplish a reroute, or the fact that the legacy trail is well-loved by the public. At some point though, trail managers should ask themselves if the cost of continuing to maintain an unsustainable trail exceeds the effort and cost to plan and implement a reroute.

Figure 2-1. The deeply rutted and abandoned trail on the left (solid line) was built without physical sustainability principles in mind.

The trail on the right (dotted line) is nearby and is well-located on a hillside at an average grade appropriate for the prevailing hillside slope and with frequent grade reversals. Cibola National Forest, New Mexico. USDA photo by Kerry Wood.

Physical Sustainability Physical sustainability is a subset of environmental sustainability. This notebook focuses mainly on physical sustainability concepts. The alignment of the trail and location on the landscape, as well as the prevailing soil type and the effect on surrounding natural resources, determine if a trail or trail segment is physically sustainable. The way the trail and trail features are designed determines how the trail will hold up under the impacts of users and anticipated extreme weather events and natural disasters. The most physically sustainable trails are constructed without needing trail structures, such as waterbars, steps, retaining walls, or tread armoring (fig. 2-2).

Figure 2-2. A physically sustainable trail doesn’t depend on building drainage structures to drain water off the tread and resist erosion. It is aligned along the elevation contour with an undulating pattern of crests and dips, called grade reversals. Pike-San Isabel National Forests, Colorado. USDA photo by Dani Cook.

Characteristics of a Physically Sustainable Trail

• Requires only light seasonal maintenance.

• Has moderate trail grades less than 7 percent, is routed across sloping terrain, and, where soils and local rainfall patterns allow, may have short steeper segments with up to a 15-percent grade.

• Located on stable soils that are not easily erodible and with features that can withstand use with minimal erosion or damage to the trail tread.

Designed to anticipate the effects of the type of severe weather events, wildfires, and other natural disasters most likely to occur in a given area.

• Is “hydrologically invisible” on the landscape. In most cases, the trail follows the contour of the hillside and does not disrupt the flow of water down the hillside or has reversals in grade (a.k.a.

undulation) that forces water to drain off the tread without constructed drainage structures.

You are attaining physical sustainability where you can:

Keep water from running down the trail.

Keep tread material well-drained and on the trail.

Water Flow Water has the power to shape landscapes by moving soil. Improperly managed water can incise tread, remove vegetation, destroy habitat, and deposit sediment into waterways. Water volume, velocity, and dispersion or concentration influence erosion potential.

Figure 2-3. Water and gravity join forces to erode a physically unsustainable trail. Los Padres National Forest, California. USDA photo by Scott Johnson.

Volume measures the amount of water at any given time.

The right amount of water increases soil moisture and helps soil particles stick together, making trail erosion less likely.

Too much or too little water can make a trail dusty or muddy.

Dusty or muddy trails are vulnerable to soil displacement from water, wind, and use, along with other negative impacts.

Velocity measures the speed at which water moves. Water with low velocity can enter and exit the trail without eroding soil or pooling. The faster the water moves, the more the erosion potential. Water with no velocity (or standing water) can make a trail muddy and vulnerable to use-caused soil displacement.

Dispersed flow, or “sheet flow,” describes the way water is dispersed down a hillside without being concentrated into channels. Sheet flow reduces the erosion potential of water (fig. 2-4). Physically sustainable trails are designed so they don’t capture and concentrate sheet flow coming down the hillside (fig. 2-5).

Concentrated flow occurs when sheet flow is captured and concentrated on a trail that has become rutted or incised. In general, trail managers design trails to avoid concentrated flow because it increases water volume and velocity, making erosion more likely (fig. 2-6). Concentrated flow is appropriate in limited situations, such as the inside ditch of a switchback, a seep(s) (or small spring) in the backslope, or a culvert.

Figure 2-4. Sheet flow disperses across the slope when the soil is saturated.

Figure 2-5. Grade reversals and outsloped tread are design elements of a rolling contour trail that promotes water “sheeting” across the trail. Sheet flow prevents water from being channeled down the trail where it will cause erosion.

Figure 2-6. Water has concentrated along the berm, causing erosion. Cibola National Forest, New Mexico. USDA photo by Kerry Wood.

Designing trail and trail structures that limit the time the water is on the tread is key to physical sustainability. More water carries more soil. Faster water carries even more soil. More soil loss and channeling leads to more and faster water that begins a cycle of increasing soil loss. The point is to keep water from running down the trail.

Soil Terra trails are built on mineral soil. Most soils are overlain by an organic layer of twigs, leaves, and grass (a.k.a. duff) that has to be removed to uncover the mineral soil. Mineral soils are mixes of silt, sand, and clay. The percentages of the mineral material determine how a trail drains water and how it holds up under use. The mix greatly affects how trails are designed, maintained, and managed.

Protecting soil against erosion is critical in trail building.

Since amending soil is impractical on a large scale, you’re stuck with the soil you have. It’s best to locate or relocate trails on stable soils that drain water well and hold up under use.

Soil types vary greatly from location to location. If you’re not sure what soil exists in a certain area, you can ask a soil scientist or an experienced local trail builder and learn how to field identify different types of soils. The USDA Natural Resources Conservation Service web soil survey is a good source of information about soils common in your area;

your local county cooperative extension service office can also provide helpful information.

https://usdagcc.sharepoint.com/sites/fs-wo-lat134/_layouts/15/Doc.aspx?sourcedoc=%7BAF290AE1-643E-4D82-81EC-608CCDF8B37B%7D&file=Prepared%20Questions%20and%20Answers%20Nov%2030,%202023%20Rec%20Hearing.docx&action=default&mobileredirect=true https://websoilsurvey.sc.egov.usda.gov https://websoilsurvey.sc.egov.usda.gov https://extension.org/find-cooperative-extension-in-your-state/

Table 2-1. Soil types and suitability for trail work

Soil type

Feel or “texture” Tips for trail work

Sandy Grainy Avoid in steep grades because the sand particles don’t bind well together.

Silty Floury Avoid in low-lying areas that do not dry out as quickly.

Clay Smooth Avoid in low-lying areas that do not dry out as quickly.

Loam Soft with some graininess

Best for trail work. Drains well while holding its structure.

Sandy soils are coarse with space between the particles, making them highly permeable and quick draining. The sand particles don’t bind well together, so they compact poorly, displace easily, and should be avoided on steep grades.

Over time, gravel and rock will pop out of the tread of sandy soils (fig. 2-7).

Figure 2-7. Sandy soils are easy to drain, but don’t bind well together and are not desirable for trail building. USDA photo by Matt Able.

Silty soils are somewhat permeable. They hold some water and can become muddy and slick. They compact well and provide a stable surface when dry. In low-lying areas that are slow to dry out, structures may be required to provide a stable trail tread under heavy use. Silty soils can also be used to build trails with slightly steeper grades than in sandy soils. With sufficient gravel and rock, silty soils have moderate binding potential and reduce the frequency of rocks popping out of the tread (fig. 2-8).

Figure 2-8. Silty soils hold water when they are wet and are floury when dry. They are best suited for trail building when mixed with gravel and rock. USDA photo by Matt Able.

Clay soils compact very well when moist but become extremely sticky, slick, and susceptible to damage when wet. When occurring with adequate rock and gravel, clay soils can create a strong trail tread that resists erosion.

However, when the clay is saturated, the tread can easily be displaced due to the swelling characteristic of clay (fig. 2-9).

Figure 2-9. Clay soils hold water and swell when wet. They can create a strong tread when combined with gravel and rock. USDA photo by Matt Able.

Loam is excellent soil for constructing trails. Loamy soil—a mixture of sand, silt, and clay—is the most desirable soil for constructing trails because it is permeable, compactable, and less of a mess when wet. Soil without a combination of clay, silt, or sand will fail in certain conditions (fig. 2-10).

Figure 2-10. Loamy soil is a mixture of sand, silt, and clay and is great for trail building. USDA photo by Matt Able.

Trail Use Impacts Trail users affect the physical trail as well as surrounding plants, animals, and cultural areas. Different use types have different impacts (table 2-2). Trail creep, rutting, widening, and braiding are results of use compacting and displacing soil. Wildlife can also move out of an area due to noise and plants can be trampled. Greater access to public lands can also mean greater access to important cultural sites and sacred areas.

While water and soil characteristics determine physical and, in part, environmental sustainability, public satisfaction partially determines social sustainability.

Savvy trail managers develop maintenance and construction strategies to balance impacts while providing a wide variety of trail opportunities for an equally wide variety of use types.

Compaction. The right amount of compaction, combined with good drainage, is necessary for a trail to hold up under use and to resist erosion. Too much soil compaction can decrease soil porosity, which limits infiltration and water drainage and leads to erosion and trail degradation. The resulting impacts are accelerated on steep trails with inadequate drainage. Too little soil compaction makes the trail tread loose and susceptible to displacement.

Displacement. Shoes, hooves, and tires flick muddy or dry and loose soil to the sides or even off the trail. Soil displacement will deepen trail tread over time, potentially trapping water, breaking down trail features, or causing users to create parallel routes.

Table 2-2. Common effects of different use types on natural surface (terra) trails

Use types Common effects Mitigation strategies

Foot travel Trail widening (users avoid wet areas or travel side-by-side)

Reroute around low or wet areas;

install causeway or drainage structure;

use vegetation or barriers to constrict traffic width

Foot travel and equestrian riders

Trail “creeps” downhill (users travel on outside edge); trail damage in wet areas

Reroute around or fix wet areas; use barriers on outside edge

Mountain bike riders

Overly insloped or “banked” turns

Reroute to reduce frequency or severity of turns;

armoring not recommended on bicycle trails

Motorized use

Rutted, wet soil;

displaced rock in stream fords

Public…

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