Basic Trail Maintenance
Trails take a beating every year from the elements and from heavy or improper use. Routine maintenance helps to keep trails safe and fun. We’re going to show you some of the basics, things you can do to keep trails in good shape, now and in the future. A good trail is one that is easy to follow and well maintained. Each trail is designed, constructed and maintained to meet specific standards. These standards relate to the recreational experience the trail is intended to provide. The level of difficulty to negotiate it, the amount of use expected and the physical characteristics of the land.
You need to know the specific standards for the trail you are maintaining. Who was the trail designed for and what are the particular maintenance standards you need to follow. Once you know the standards, you need to be most concerned with correcting unsafe situations. You’ll also be responsible for minimizing natural resource damage and fully restoring the trail to its original design standard. Whatever the reason, doing maintenance when the need is first noticed will help prevent more severe and costly damage later.
Things You’ll Need
Before heading out, make sure you’re prepared for the work ahead. The most important thing in trail maintenance is your personal well-being and safety. Drinking water, lip moisturizer, sunscreen, sunglasses, insect repellent and personal medications are important items to take along with you. Pants and long sleeves are the best protection from scrapes, insects and sunburn. Good leather boots at least eight inches high offer the best support and ankle protection. Ankle high hiking boots are ok for some trail work, but, sneakers or tennis shoes do not give enough support or protection. Rubber boots might be the norm for boggy trails. Having a positive attitude about safety is most important and don’t start the job until you have the proper equipment. Safety gear includes hard hats especially when working in timber or in area with falling rock or swinging tools. Eye protection for cutting or rock work and ear protection near chainsaws or rock drills. As a crew you’ll also need a first aid kit and some sort of communications plan. The project leader should have a job hazard analysis that identifies the specific hazards of the work you’ll be doing and should hold safety briefings before you start work especially on something new. Now that you’re ready, we’ll explore some of the basics of trail maintenance. Trail clearing, tread maintenance, switchback maintenance, surface water control, rock and wooden structure maintenance, marking the trail and trail obliteration.
The trail corridor is a zone which includes the trail and the area to the sides and above it. The trail corridor needs to be unobstructed for the safe passage of hikers, stock and riders. The clearing limits for hiking and mountain bike trails are about 3 to 4 feet wide and 8 to 10 feet high. For pack stock trails, they are usually 6 to 8 feet wide and 10 feet high. Your specific trail standards give you exact dimensions. Keeping the trail corridor open requires that you remove seedlings, prune overhanging limbs, log out fallen trees and cut down unstable leaners.
Clearing begins by removing tree seedlings which are beginning to crowd the trail corridor. The longer they’re left to grow, the harder it will be to eventually remove them. You can yank the seedlings out by the roots, or, thin them out with loppers or small power tool. Cut them off at ground level, taking care not to leave pointed stubs. Overhanging tree branches may also crowd the trail corridor. Cut the limbs off within half an inch of the tree trunk. Make a shallow undercut first, then follow with the top cut. Do not use an axe for pruning. If over half the tree needs pruning, it’s usually better to cut the tree down. Throw limbs and stems off the trail, butt ends first where they are least visible.
The trail corridor may be blocked by fallen trees. Logging out a trail means cutting away trees which have fallen across it. The size of the tree, restrictions on motorized equipment and your skill and training will determine whether chainsaws, cross cut saws, bow saws or axes are used.
Cutting timber is hazardous whether using a chainsaw, crosscut saw or axe it’s important to have the proper training certification and concern for safety. The most basic logging techniques involve an undercut and a top cut. Sometimes side cuts are also needed to relieve tension in the log. Cut the log out as wide as your normal clearing limits. Experienced trail maintainers have everything carefully planned so that once the cuts are made, the log almost naturally moves to the side of the trail — Or, can be easily be rolled outside the clearing limits with a little leverage. Don’t leave a log end suspended in mid air. Make another cut to drop it to the ground. Leaners are trees which have not fallen, but are leaning across the trail. If the leaning tree is within the trail clearing zone, it should be removed. It’s a judgment call whether or not to cut down a leaner outside the clearing zone. Felling a standing or leaning tree, especially one that is hung up in other trees can be very hazardous. Only highly qualified sawyers should do it. If you’re uncomfortable with your ability to cut a tree, due to its hazards or your lack of experience, walk away from it. Leave it for someone more qualified. You’ll be exercising sound judgment if you do.
Maintaining the Tread
The tread is the surface of the trail that you walk on. The tread needs to be maintained at the minimum width for which the trail was designed. An out-slope tread is one that is lower on the outside or downhill side of the trail than it is on the inside or bank side. Out-sloping lets water run naturally off the trail. A 2 foot wide trail would have an outside edge 1½ to 2½ inches lower than the inside edge. Slough is soil, rock and debris that has slid onto the inside of the tread, narrowing it. Sloughing can also cause hillside trails to creep downhill.
Slough needs to be removed. This is hard work. Loosen compacted slough with a mattock or pulaski. Then remove the soil with a shovel or mcleod. After the slough has been removed, reshape the tread to restore its outslope. Berm is soil that is built up on the outside of the tread forming a barrier that prevents water from running off the trail. In most cases, the berm should be removed so outslopes can be maintained and water can easily drain off the trail.
Fixing Downhill Trails
Trails can move downhill over time because of sloughing and overuse of the outside edge of the tread. Livestock, mountain bikers and hikers often use the outer edges of hillside trails. Ever wider trails push off the planned alignment or bench of the trail often in the soft soil causing the trail to creep down the hill. Your job is to bring the trail back up hill to its original location and to keep it there. Trees, stumps, logs and rocks on the downhill side of the trail help to keep the trail in place by preventing people and animals from walking the edge. Curb rocks need to be well anchored and placed at random distances so they don’t look like a wall.
You may have to remove an occasional stump in routine maintenance but before you do, consider whether a stump should be left to help keep the trail from creeping downhill. Removing them is a lot of work. The larger the stump, the more difficult. Explosives and stump grinders are sometimes good alternatives for removing stumps. But chances are you’ll have to do the work by hand.
Removing Embedded Rocks
Your specific trail maintenance standards may also call for removing embedded rocks. Use good judgment here as to whether the rock is moveable or better handled by blasting or rerouting the trail. Rock bars are great for skidding medium to large rocks. Use the bars to pry rocks up out of the ground and then to guide them around. When crew members have 2 or 3 bars under various sides of the large rock, they can apply leverage to the stone and virtually float it to a new location. Increase the leverage of your rock bar by using small rocks or logs as a fulcrum. Be careful when rolling rocks off the trail. An out of control rock can knock down small trees, wipe out trail structures, start rock slides and even worse, hit someone on the trail below you. Once a rock is loose however, do not try to stop it. If there is any possibility of people below, close the trail or road or post sentrys until the rock work is done. Lifting rocks should be a last resort. If you need to lift rocks, be sure to keep your back straight, bend your knees and lift with the strong muscles of your legs.
Filling holes, turnpikes, or washed out sections
For this you’ll need replacement fill material. A mixture of sand, gravel and small well graded angular rocks work well. Creek bottoms which are replenished by storms and seasonal water flow, the cut bank of the trail itself and the base of slopes or cliffs where heavy runoff or gravity deposits sand and gravel are good places to find fill materials. Very fine soils like silt and clay do not drain well, are slippery when wet and are highly erodible. Dark colored organic soils found in bogs or swamps retain water. None of these make good fill material. The hole you dig for fill material is called a borrow pit. It should be as close to the work site as possible, but screened from view. A large deep pit is better than many small or shallow ones. Be careful not to destroy aquatic or riparian habitat when digging your pit. When you dig the pit, save all squares of vegetation. Keep them in the shade and as moist as possible by covering them with wet burlap. When you’ve taken out all the fill material you need, fill in the pit by collapsing the sides. Once the pit has been filled in, replace the grass squares, camouflage the area and access trail with boulders and deadwood. Reseed if necessary with compatible grass or ground cover.
Maintaining Switchback Trails
Switchbacks usually require more maintenance than straight sections of trail. Slough, erosion and trail short cutting all take a toll on switchbacks. Maintaining the outslope and inslope of the switchback and the shape of the turning platform is critical. First, remove slough and berm from the trail. Next, re-grade the outslope of the lower trail lag and the inslope of the upper lag. Insure drainage by cleaning debris from the inside edge of the upper lag, and the ditch along the inside of the turning platform. Last, but not least, close off shortcuts to stop erosion and to keep users on the trail. Block off the shortcut with brush logs or rocks. Thorny plants transplanted on to the shortcut will persuade users to stay on the trail. Use your imagination but keep things looking natural. However, where traffic is heavy or there’s a lack of screening, consider constructing a rock wall or a log barrier along the top leg of the switchback.
Diverting Surface Water
Diverting surface water off the trail is the most important job in trail maintenance. The sooner water is off the trail, the better. The primary ways to do this are maintaining drainage structures and removing standing water from the trail. Usually, drainage structures are the only things keeping a trail from washing out. It’s important that they are maintained. The drainage structures should be cleaned thoroughly to allow for an entire season of traffic and weather including seasonal runoff.
Maintaining a Water Bar
To maintain a water bar, reshape the tread with a shovel, combination tool, mcleod or fire rake to form a funnel like apron approaching the bar. Be careful not to undermine the bar by digging the apron too deep. This allows the water to runoff the trail before hitting the bar itself. A common misconception is that water must run down the trail and actually hit the water bar before running off the trail. Instead, think of the water bar as the ultimate backup to divert water off the trail in a heavy storm or during spring runoff. Reset or replace loose water bar rocks, anchor stakes and rotten logs. Clear rocks, logs and other debris out of the lead off ditches. Make the lead off ditch wide enough to handle the expected volume of water, usually at least 2 shovel blades wide.
When maintaining culverts, you’ll need to repair, reseat, or replace those that are in poor condition. Run a shovel through culverts to remove silt and debris. If a culvert is narrower than your shovel, use the handle or a combination tool. Not all eroding trails become major problems. Some eventually stabilize by themselves, especially those on relatively level and rocky ground. However, if erosion is evident, you may need to install additional water bars, grade dips, culverts or other surface water control structures. Figure out where the water is coming from and where it is likely to go. Consider soil type, slope gradient, distance of flow and volume of water. See where erosion is occurring and do something to stop it.
Preventing Standing Water
A section of trail that is very muddy or that holds standing water is a messy problem. Trail users will often try to avoid getting wet feet by detouring around the mucky area which enlarges the problem by beating down vegetation and soil. On hillside trails, the best way to remove puddles is to restore the trail tread to its original outslope condition over the entire length of the puddle so that water naturally runs off the trail at all points. In soft soils, especially on pack stock trails, both ends of the puddle are good places to anchor large rocks to help keep stock in the center of the trail.
Correcting Problems in Treeless Areas
There are other strategies for correcting problems on trails in treeless areas. Trails that cross meadows and alpine tundra can become a lacework of paths. The problem often is that the original trail was poorly located. Without obstacles such as rocks, underbrush or trees bordering the trail, there is little to encourage users to stay on the tread. As the trail becomes difficult to use, people simply step aside to create new easier paths. Often the answer is to relocate the trail onto a side slope. The trail will be where people are more inclined to stay on it and where drainage is more successful. If you can’t move the trail, restore the trenched out trail by filling it with mineral soil or crushed rock. Crown the tread making it slightly higher than the surrounding ground to encourage water to run off to either side. Another solution is to locate the source of the water. Usually a spring or sieve and channel water away with ditches or culverts. You may also consider elevating the tread above the wet ground with a turnpike, puncheon or stepping stones. In most cases, draining a trail is easier than elevating the tread above wet ground.
Trail turnpikes need periodic maintenance. Re-crown the turnpike and fill in any holes or depressions. Inspect the retainer logs or rocks and replace or reset any that are missing or loose. And clean out the lateral and lead off ditches.
Maintaining Rock Structures
Rock trail structures require routine inspection and maintenance. Rock structures that have been built properly should require little maintenance. Even so, you should take a look at them. Inspect rock structures to see if any stones are working loose. A wall can sometimes be strengthened by chinking smaller stones between larger ones. Examine the bottom tier of the wall to be sure it still firmly embedded in solid soil or against rock. Where soil has eroded away, you may be able to prevent further undermining of the foundation by piling heavy stones against it. Add replacement fill where needed. Rock structures that are loose and wobbly should be dismantled and rebuilt. The same stones can be used for the reconstruction, often in the same order. At stream crossings or fords, remove large rocks from the tread area and make sure the approach apron does not have abrupt drops.
Maintaining Wood Structures
Load bearing structures made of wood should be inspected for signs of rot and deterioration. Often bridge and puncheon inspections are rather elaborate and beyond the scope of routine trail maintenance. However, you should look at them and report obvious problems. To get a sense of whether a timber is rotten, stick it with a knife. If the blade goes in easily, the wood has probably lost much of its strength. As part of your routine maintenance job, remove all debris from wooden surfaces. Moss, pine needles, leaves and debris on bridge and puncheon decking, hold moisture that causes decay. Next, look for nails, spikes or rebar that have worked loose. Drive them flush with the wood or remove them. Reshape the approaches to bridges and puncheons and clean out drainages that keep water from running onto it.
A well maintained trail is obvious. The more clearly defined a trail is, the less need there will be to mark it with signs, blazes and cairns. The amount and type of signage varies by jurisdiction and the type of recreational experience being provided. The forest service has national guidelines which cover all types of trail signing. There should be a detailed sign plan in effect for the trail you’re maintaining. Repair damaged signs and install replacement signs or markers where the originals have disappeared. You should also report any down, inappropriate, or dilapidated signs to the project leader.
Replacing Trail Signs
Make sure replacement signs are put in the correct location visible, yet not an obstacle to trail users. To install a signpost, dig the hole at least 20 inches deep. The hole should be at least the width of your shovel. A post hole digger often works better than a shovel to remove loosened soil and rock. Once the hole is dug, drop the post into the hole. Pack a few rocks around the post and tamp them down to hold the post in place. Fill the hole with rocks and soil, tamping as you go. Top the hole off with soil and pack it down. Some signs and plastic markers may be nailed or bolted to trees rather than to posts. Aluminum rather than steel nails are often used. Leave about a ½ inch gap between the sign and the tree to allow for additional tree growth to occur.
Using Painted Blazes
Blazes are a traditional way of marking trails. One that is being replaced by signs or markers in many areas. In some parts of the country, painted blazes are acceptable. You should cut new blazes only if given specific instructions to do so.
Using Cairns to Mark Trails
Cairns are used to mark trails in treeless areas. They are effective year round because they are visible even when the tread is covered with snow. Cairns need to be conspicuous so they are easy to see in low visibility conditions. They should be 3 to 4 feet wide and 3 to 6 feet high. Stack large flat rocks into layers, making sure to bridge each joint. Each layer should slope slightly to the center so that gravity will stabilize the cairn.
Restoring Trails to Their Natural Condition
Sometimes it’s necessary to abandon a trail and restore the site to its natural condition. There aren’t any fixed approaches for doing this. Each site should be evaluated for its potential to re-grow and heal. At sites that are moist and relatively flat it may be possible to simply block off the trail and allow rehabilitation to proceed naturally.
At the other extreme, dry steep sites take a lot of work. The first step to obliterate a trail is controlling surface water and erosion. Drainage structures should be left intact. However, you will need to remove culverts and replace them with ditches. Check dams and water bars might be needed to stop erosion. Next, break up the tread by de-compacting the soil with hand tools, stock and harrow or heavy equipment and then reshape it back to its natural contour.
Finally, you need to stop people from using the trail. The most effective way to do this is to block the route with logs, rocks and brush. Be sure to block the entire route or at least enough of it to discourage use. Blocking just the ends of the trail usually isn’t enough.
Re-vegetation with native species is the final step. Transplanting vegetation planting nursery stock and seeding with native or commercial mixes are all possibilities. Introducing weed species is always a concern. Well, now you know some of the basics.
Once you actually construct or maintain a trail, you’ll never look at one the same way again. You will have a much better idea of why a trail is where it is and what keeps it in place. And, you should feel good knowing you’ve helped make some great national forest trails safe and enjoyable.