TRAIL WORK TASKS
Trail work involves three activities. Trail assessments, trail maintenance, and trail construction. Trail assessments and trail maintenance are divided into basic and major categories.
TRAIL ASSESSMENTS
Basic trail assessments are overseer inspections and evaluations of trail routes, tread, structures, and use on their trail segment to identify adverse conditions and trends of change that require trail work. They also include overseer reporting of changes to trail segments as input for trail-guide books and maps.
Major trail assessments are district manager and trail partner formal inspections and evaluations of trail routes, tread, structures, and use to identify major trail maintenance or trail construction projects.
Both basic and major trail assessments examine the same factors. These are: trail tread impacts due to water flow and trail use, the condition of trail structures, vegetation growth, trail markings, and unauthorized connecting trails, fire rings and camp sites, and general vandalism.
Trail Tread
Water flow does the most damage to trails, and many design factors are used to mitigate water flow and the damage erosion can do. As familiarity with the trail is gained by repeated visits, changes to the tread will be noticed.
A healthy tread will have water flowing off the trail over wide areas (sheeting flow). The tread will be sloped sideways downhill about 1-2 degrees (out-slope). If the outside of the trail becomes higher than the inside, water will flow down the tread in a narrow path. This will start eroding away the inside and may form gullies.
Another problem that arises with trails on the side of a hill/mountain is that, over time, the trail becomes compacted and some of the soil washes away. Roots will become exposed on the uphill side, or out-slope will become too steep. People will then tend to walk on the downhill side of the trail and the trail will gradually widen and move downhill. This is known as trail creep.
Trails on flat surfaces tend to become compacted. The degree to which this happens is a factor of soil composition and trail use. Several conditions are of concern. First, the tread on which people walk may be narrow and become a small gully; people then will walk on the area to the side of the tread (trail braiding). Another condition is that puddles of water will form in various places; people will walk around the puddle (trail spreading). The result of these conditions is that a wider area is denuded of vegetation, and the trail becomes an unpleasant place to walk.
In some cases, erosion will gradually take away soil and small rocks will become prominent. This can result in a tread with a surface of loose rock, which can be slippery and dangerous for a hiker, particularly if a slope is steep and downhill.
Trail Structures
The first task in assessing trail structures is to walk the trail segment and prepare an inventory of what structures exist and where they are. The purpose of this is to simplify the task of condition assessments that will follow.
Trail structures include such things as water diversion and water slowing constructions, bridges, stiles, and steps. From an assessment standpoint, the major questions to be answered are: Is their condition sound or have they deteriorated to the point they need repair or replacement (e.g., is wood rotten?)? Have rocks moved from the place they were installed? Has dirt washed away? Are areas behind water diversions full of dirt and duff? Are additional trail structures needed?
Water diversions are built of dirt, wood or rock (water bars) or are constructed as an aspect of trail design or reconstruction (dips).
Visual inspection will reveal their condition, particularly after a period of rain. The pattern of water flow washing leaves and other duff from the trail will indicate whether water is flowing off the trail as intended. If the area behind a water diversion is full of dirt, then it is useless. If the drainage path from a water diversion is clogged with dirt, branches, and leaves then it isn’t doing its job. If the drainage path was built too narrow or has become eroded into a narrow gully, then down slope erosion is likely. If erosion is occurring down the trail from the water diversion, then it isn’t diverting the water; why not needs to be determined.
If erosion is occurring off the trail and downhill from a water diversion, then soil is being swept at some point into area waterways. Digging a hole downhill from the diversion and filling it with rock is one way to slow water and encourage infiltration into aquifers instead of runoff. A barrier of a log or rock dam and duff (similar to compost) can filter and slow water flow, reducing erosion and filtering out silt particles.
Check dams are put into tread when water flows down a trail and cannot for one reason or another be diverted off the trail. These are designed to trap eroding soil and sediment. Their intent is to slow water flow. A common error is to put them too far apart. As water flows over the check dam, it curls as a wave does at the beach. It then erodes under the check dam creating a high step. Hikers then walk around it, creating trail spreading. This condition should be noted, as more check dams will be needed and a height of 6 to 7 inches for the step re-established. Note also that the check dam should have about an inch of log or rock showing above the trail to catch sediment. These must be periodically cleaned to maintain the trap.
Bridges, stiles, and steps should be examined to determine their condition. If a sign is painted and the paint is wearing off, then that should be noted. If bridges are becoming unstable or planks/stringers are rotting, then that should be reported. Steps can become unstable due to erosion of their bases or improper construction.
Vegetation
Vegetation grows along the side of a trail and can obstruct passage of hikers if not controlled. Such things as Poison Ivy and briars can cause skin damage and tear clothes. Ticks hang on vegetation to drop on or jump on hikers. Such things as Mountain Laurel can grow to a point where trails are blocked. Thus clearing vegetation to standards for the trail concerned is important.
A trail assessment notes where vegetation is impeding hikers or putting them at some risk. A first step is to walk a trail segment and note the types of vegetation present along the trail. The difficulty of keeping vegetation cut back and the tools that will be needed will be determined by this inventory. Then an assessment notes the extent of vegetation clearing needed to maintain the trail.
Trail Markings
The first step in doing an assessment of trail markings is to walk the trail segment and note where each sign or blaze is located. Each should be examined to determine if they are properly placed, and their condition and visibility.
Signs are placed generally at trail entrances and intersections or to point to a destination (such as a shelter or overlook). Rain, weathering, and vandalism can result in signs becoming unreadable or missing. Vegetation can grow up and obscure a sign. An assessment should note whether or not a sign is where it is supposed to be and its condition.
Blazes are placed along a trail so a novice hiker can follow the trail and not get lost. As a rule, a hiker should be able to see a blaze ahead and a blaze behind him or her. At trail intersections, there should be two blazes stacked to indicate the turn and one or two blazes should be visible down the trail from the intersection. Rain, weathering, and vegetation growth can obscure blazes. Trees falling can eliminate them. An assessment should note the condition of blazes and where re-blazing is needed.
Unauthorized connecting trails, fire rings and camp sites, and general vandalism
In areas near where people live, residents (or park users) will often create an entrance trail from residential areas (or picnic areas) to trails. Sometimes children riding bicycles will use such trails. They can suffer severe erosion and impact the main trail. When children ride their bicycles, they may build jumps and other structures, and create a system of braided trails, severely impacting the environment. Unauthorized connecting trails should be noted and included on inventories of trail segments.
Unauthorized fire rings and campsites may be created by neighborhood children or by backpackers who can’t make it to a shelter or campsite. These should be noted and broken up, with branches and other wood dragged in to discourage further use.
General vandalism includes such things as paint on rocks or trees, or destroyed trail structures. When found, such actions should be noted.
TRAIL MAINTENANCE TASKS
The fundamental purpose of trail maintenance is to conserve the pathway in its current location, in a condition that permits reasonably safe hiking. Conservation requires early action when deteriorating conditions are first noticed. This usually means stopping erosion by maintaining water flow characteristics of the pathway generally (to allow sheeting of water rather than channeling of water flow), and maintaining water diversions so they work as designed. It may also mean improving pathway characteristics so sheeting of water is improved or installing additional water flow controls and diversions. If trail creep, braiding, or spreading is noticed, then early action to improve the pathway to stop the deterioration (e.g., puncheon, bridging wet lands, turn-pike) is vital.
Basic trail maintenance includes overseer trail work and overseer led work trips to:
- Maintain and make minor repairs to trail tread,
- Restore trail structures,
- Clear vegetation, branches, and trees (up to about 8” diameter) from trails,
- Maintain trail blazes and signs, and
- Pick up litter and trash.
Basic trail maintenance also includes assistance provided overseers by certified saw operators and by crosscut sawyers to clear trees of larger than 8” diameter.
Maintain and make minor repairs to Trail Tread
Maintaining and making minor repairs to trail tread includes such things as restoring the out-slope of side-hill pathways when a lip of dirt and duff builds up on the downhill side, cutting exposed roots and returning tread to its intended location when trail creep is apparent, building short sections of turnpike to eliminate trail spreading, and making tread on flat land somewhat wider and more passable when trail braiding is apparent.
Often when trail tread is built, or if trail creep has occurred, roots of trees will be surfaced and will lie loose above the trail surface. These roots can trip hikers. Another hazard that arises is when small trees are cut near the surface, and the trail tread passes over them. The small cut part of the tree protrudes as the tread is compacted and can cause a hiker to trip and fall. Such a tripping hazard can also arise when rocks protrude two or three inches above the surface as trails are compacted. All such tripping hazards should be removed.
Restoring Trail Structures
Restoring trail structures includes such things as clearing leaves, branches, and duff from water diversions, and restoring them to original condition (or improving water flow by making narrow channels wider so water sheets off), clearing soil from the uphill side of check dams and filling in down slope so the height of a step is 6-7 inches, and replacing rotten wood or resetting stones in water bars or check dams.
District Managers will provide guidance on replacing and repairing water diversions. Trail partners differ in their preferences about types of wood to use (i.e., natural or treated), whether trails may be reshaped to create dips, and whether or not prior clearance is needed.
If replacing a wood water bar with natural materials, fallen trees are used. A tree section long enough to stretch about a foot off the uphill side of the trail to about two or three feet off the downhill side, and about six to eight inches in diameter is used. It will be installed at a 45 to 60 degree angle. If the tree section selected has not lost its bark, then the bark must be removed prior to installing it in the ground. Hard woods such as black locust or oak are preferred. A narrow trench is dug along the 45-60 degree line deep enough to firmly seat the tree section. On the uphill side of the water bar, the trail and downhill side is dug away and shaped so that water will flow off the trail before reaching the water bar itself. Dirt is piled up against the water bar, and over it. It is desirable that the shape of the drainage be such that the water will sheet off the trail and not flow into a narrow channel. On the downhill side of the water bar, a hole should be dug or an obstruction placed to slow and trap water sheeting off, with the purpose of minimizing off-trail erosion.
If acceptable to trail partners and soil has enough clay, and the slope of the trail is not excessive, then a wood water bar can be replaced with a dirt water bar.
If rocks are available, then a rock water bar can be built. It is installed by selecting fairly large rocks with one side being somewhat level. Holes are dug into which rocks will be firmly seated, with flat sides up. The uphill side is then shaped as for a wood water bar, and small rocks and dirt are used to fill holes and shape water flow so it will sheet off the trail.
If trail partners permit it, when a trail undulates across a slope, it can be shaped so that there is a dip in the trail. The trail is shaped so the out-slope is somewhat greater than normal, say 3 - 5 degrees, on both sides of the dip. The dip is designed so the water sheets off.
Clear Vegetation
Clear vegetation generally to about two or three feet either side of tread centerline. Such things as poison ivy, briars, brambles, and thorn bushes should be cut back further. This general standard may vary per trail partners. District Managers will inform overseers. The basic intent is to allow a hiker in shorts to pass along the trail without being cut up, and to reduce the risk of tick or chigger bites and infections (Wilderness standards are less than for non-wilderness areas). Prune branches that intrude into the trail and to a height of about eight feet. When pruning branches, cut near the bole of the tree. Avoid cutting the tops out of small trees, the branches will grow over the trail. Prune branches not only from the trail tread, but also note when vegetation and branches block blazes or signs. A clear sight line to blazes and signs should be maintained.
Downed trees up to about 8” in diameter should be cleared with a handsaw. If larger trees are present, contact a certified chain saw operator or crosscut sawyer to aid in cutting the trees. Cut trees to the width of vegetation clearance, except where there is a problem of ATVs using the trail. If ATVs are a problem, cut no wider than 23” (insufficient room for an ATV to pass).
If the top of a tree has fallen over the trail, clear branches back a greater distance than vegetation clearance. The reason is that vegetation tends to grow amid the branches and intrude into the trail. When they are briars or vines, they entangle and become difficult to keep clear.
Maintain blazes and signs
A cardinal rule is not to over-blaze. Another is to paint neat blazes. In general, a hiker should be able to see a blaze in the direction he or she is hiking, and a blaze behind in the opposite direction he or she is hiking. Blazes should generally be at eye height for the average hiker, and placed on healthy trees at least eight inches in diameter. These rules apply for all trails.
The Appalachian Trail is marked with white blazes. Side trails for the Appalachian Trail are marked with blue blazes. The Tuscarora Trail is marked with blue blazes. Side trails for the Tuscarora Trail are marked with various color blazes. Each blaze is a two inch by six inch rectangle.
Other trails are marked with blaze colors prescribed by trail partners. Except for blazes on Forest Service trails, each blaze is a two inch by six inch rectangle. Forest Service trails are marked with a two inch by six inch rectangle over which is a two inch by two inch square.
Turns in a trail are marked by two blazes, one over the other. In the Shenandoah National Park, dual blazes are painted in a straight line. In all other areas, the top blaze is offset two inches in the direction of a turn.
When marking an intersection of multiple trails where a hiker might become confused, mark the direction of travel with two visible blazes that can be seen from the intersection.