Dirt Dissected: Trail Anatomy 101
by Danny Bernstein
“Stand up straight, just like your momma taught you,” says Dwayne Stutzman, the trails specialist for North Carolina State Parks. He’s talking to Lenny Bernstein, who is positioned about 100 yards in front of him and acting as a surveyor’s stick. Stutzman uses an inclinometer to measure the angle to the top of Lenny’s head, which is roughly the grade of the future trail. Stutzman wants to keep the angle less than 10 percent, so that the trail grade is not too steep. A grade above 10 percent will encourage more trail erosion and make it more difficult for hikers, so Dwayne feels that a 10 percent slope is a good guideline.
Stutzman is assisting the Carolina Mountain Club build a new section of the Mountains-to-Sea Trail (MST), west of Balsam Gap, N.C. Mile by mile, volunteers are transforming a hillside of trees, rocks and dirt into a trail. The CMC negotiated with the state and the Blue Ridge Parkway on the general route for this 15-mile segment, all on Parkway land. The state conducted an Environmental Impact Study over six years ago to determine how the proposed trail route would affect endangered species and water quality. Once the state and the Park Service approved the route, volunteers from the Carolina Mountain Club began the dirty work of actually building it.
As the state’s liaison, Stutzman is responsible for flagging the actual route. He bends the trail around large boulders and trees to minimize impact to the forest. He also tries to position the route on the upside of trees, where there are fewer roots, all while following the natural contour of the land and creating a gentle slope. In addition, he must be careful to safeguard endangered plants nearby. All these considerations produce the twists and turns of the finished trail.
Once flagged, the volunteer crew bushwhacks in and cuts the undergrowth of vines and bushes, creating the standard four-foot wide path with an eight-foot high clearance.
Certified chain sawyers identify and saw trees that can’t be avoided, and roots are pulled out using a griphoist: one end of a chain is wrapped around the tree trunk, while the other end goes around two large trees nearby. When the griphoist is cranked up, the tree roots come out. It’s like a child who ties one end of a string around a baby tooth, the other end to a door knob, and then closes the door.
Next, the trail needs to be benched, which means leveling and evening the slope of the trail. Without a bench, the trail would soon be covered by dirt and soil sliding down the hill. Coweeta dips-low gullies between two high spots-direct water off the trail without water bars. Coweeta dips also create an undulating trail, allowing hikers to change pace, which is easier on their feet.
“No more water bars, now we talk about water diversions,” explains Piet Bodenhorst, head of the CMC trail crew. “Hikers like them better than water bars because logs are slippery.”
Hikers tend to walk on the outside, downhill side of a trail, so logs and rocks are left on the downhill edge to encourage hikers to move uphill. The crew rakes some foliage back on the trail, to make it look more natural and to prevent erosion. The final step is painting white circles, the MST symbol, on trees about a thousand feet apart.
Once built, the trail is divided up in two to three mile sections and adopted by volunteer trail maintainers who keep the trail open and free of obstructions. The volunteers will visit frequently every year to see how well the trail has stood the test of time and hikers’ feet. As Bodenhorst points out, “In this lush area, if you leave a trail alone for a few years, you won’t find it again.”
Trail Vocabulary
Bench-A flat, stable surface on a slope, either occurring naturally or cut by the trail crew.
Berm-The raised outside edge of a trail.
Blaze-A mark used to show the route of the trail.
Blowdown-Trees that have been toppled by wind which create an obstruction on the trail. If not cleared quickly, hikers tend to go off the trail and around the blowdown.
Coweeta dip-A low spot between two high spots on the trail, ideally one inch of elevation change for every foot of trail. Coweeta dips divert water from the trail and are easier to maintain than water bars.
Grade-The degree of inclination of the slope of the trail. Percent grade is the relationship between horizontal distance and vertical gain.
Switchback-The zigzag course on a steep incline which allows the trail to maintain a reasonable grade. Switchbacks make the trail longer than if it went straight up the mountain but also makes it less strenuous.
Water bar-A drainage structure with a rock or log barrier embedded at an angle on the trail. Water flowing down the trail will be diverted by the slop or the barrier. Trail crews are discouraged from putting in new water bars since they get clogged with leaves and need to be cleaned out regularly.
