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Trail Construction and Maintenance Notebook

Trail Planning

A good trail may appear to have "just happened," but that appearance belies an incredible amount of work in scouting, design, layout, construction, and maintenance. Although this guide focuses on actual dirt work, we want you to understand that solid planning is essential. Keep this in mind when designing, constructing, and maintaining trails (figure 2).

Photo of a trail looking toward a peak and overlooking a valley.
Figure 2—Design and construct your trail to fit the land.

Recreation trails are for all people. They allow us to go back to our roots. Trails help humans make sense of a world increasingly dominated by automobiles and pavement. They put us in touch with our natural surroundings, soothe our psyches, challenge our bodies, and allow us to practice traditional skills.

Human psychology also plays a role. A useful trail must be easy to find, easy to travel, and convenient to use. Trails exist simply because they are an easier way of getting someplace. Many trails, such as wilderness trails, motorcycle routes, or climbing routes, are deliberately challenging with a relatively high degree of risk. Rest assured, however, that if your official trail isn't the path of least resistance, users will create their own trail. Your trail must be more obvious, easier to travel, and more convenient than the alternatives or you're wasting your time and money.

Accessible Trails

The Forest Service Trail Accessibility Guidelines (FSTAG), which became official agency policy in May 2006, recognize and protect the environment and the natural setting while integrating accessibility where possible. These guidelines are available at

Forest Service trail designers must approach the design of hiker or pedestrian trail projects that connect to an accessible trail or trailhead with the intent of developing trails that are accessible to all users, including those with disabilities. Four "conditions for departure" waive the accessibility requirements for most existing primitive, long-distance trails, and new trails built on very steep terrain. The guidelines apply only on National Forest System lands.

To help trail designers integrate the requirements of the Trail Accessibility Guidelines into planning, design, construction, and maintenance of trails, the Forest Service developed the "Accessibility Guidebook for Outdoor Recreation and Trails." The guidebook provides detailed information about accessibility requirements in an easy-to-use format with photos, illustrations, design tips, hotlinks, and sidebars. The guidebook is available at

Best Friends

The three best friends of a trail worker are:

  • A good baseline inventory of the trail
  • A current condition survey
  • Problem area reports

Hang out with these friends... get a clue.

Avoiding Trail Disasters

If you've ever encountered a trail disaster, chances are that it resulted from short-circuited planning. Acts of God aside, some of the worst trail problems result from not doing the hard work of thinking before putting on the gloves and hardhat. Some glaring examples are:

  • Building out-of-rhythm sections (abrupt turns). Why did this happen? The trail's rhythm and flow weren't checked before cutting it in.

  • Water funneling down and eroding the tread. Why did this happen? The trail grade was designed too steep.

  • Multiple trails. Why did this happen? The trail wasn't laid out in the best place to begin with.

Planning is stupidity avoidance. Do good planning for all levels of trail work.

Good planning also includes monitoring the trail's condition. It's hard to do good planning until you have some idea of the current situation and trend.

Our focus in this notebook is field work, but other important work goes into trail planning. Requirements for trail planning vary, but they usually include consulting soil scientists, bridge and geotechnical engineers, fisheries and wildlife biologists, recreation planners, landscape architects, and persons skilled in documenting environmental and permitting requirements.

Planning the Route on the Map

Be certain you know the trail management objectives (TMOs) for your trail—things like the intended users, desired difficulty level, and desired experience. TMOs provide basic information for trail planning, management, and reporting.

Use topographic maps and aerial photos to map the potential route. On the map, identify control points—places where the trail has to go, because of:

  • Destination
  • Trailheads
  • Water crossings
  • Rock outcrops

Include positive control points—features such as a scenic overlook, a waterfall, or lakes.

Avoid negative control points—areas that have noxious weeds, threatened and endangered species, critical wildlife habitat, or poor soils.

The 10-Percent Guideline

When plotting the trail on a map, connect the control points, following contour lines. Keep the grade of each uphill and downhill section less than 10 percent. Plotting your trail with 10-percent grades on a topographic map will help keep the route at a sustainable grade. When you get into the field to start scouting the route, you'll have better flexibility to tweak the grades.

Percent Grade

  • Grade can be expressed as a percent or an angle. Percent is easier to understand.
  • Percent grade equals the rise (elevation change) divided by the run (horizontal distance) multiplied by 100.
  • Example: rise of 10 feet/run of 100 feet x 100 = 10 percent
  • Elevation change, up or down, is always a positive number.