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Trail Construction and Maintenance Notebook


Trail signs comes in two forms. Trailhead and junction signs are used to identify trail names, directions, destinations, and distances. Reassurance markers are used to mark the trail corridor when the tread may be difficult to follow.

Typically, signs are used at trailheads to identify the trailhead and the trails there. At some locations, destinations accessed by these trails and the distances to the destinations will be displayed. Signs also are used at system trail junctions (and road crossings) to identify each trail by name and indicate its direction. Signs may identify features, destinations, and occasionally, regulations, warnings, or closures.

Reassurance markers include cut blazes on trees; wood, plastic, or metal tags; posts; and cairns. Reassurance markers are more useful as the tread becomes more difficult to identify and follow. These markers help travelers identify the trail corridor when the tread is indistinct, the ground is covered with snow, or when the route is confused by multiple trails or obscured by weather, such as dense fog. National trails usually are marked periodically with specially designed tags.

The number of signs or reassurance markers depends primarily on the planned user skill level. Low-challenge trails typically will be signed with destinations and distances. Usually, the trail will be so obvious that reassurance marking is necessary only at points where users might be confused. As the desired opportunity for challenge rises, the amount of information given by signs usually drops to trail identification and direction. You may find special guidelines for wilderness areas.

Installing Signs

Trail signs are made of a variety of materials; the most typical is Carsonite or wood. Usually, signs are mounted on posts or trees. Signs in rocky areas should be mounted on a post seated in an excavated hole or supported by a well-constructed cairn.

Wooden posts may be obtained onsite or hauled in. Onsite (native) material is usually less expensive, but may have a shorter useful life. Native material looks less artificial; it may be preferred in primitive settings. Purchased posts should be pressure treated. Their longer lifespan will offset the higher initial purchase and transportation costs. Round posts appear less artificial than square posts and provide more options for custom alignment of signs at trail junctions. Posts should be at least 150 millimeters (6 inches) in diameter.

Signs should be placed where they are easy to read, but far enough from the tread to leave clearance for normal traffic. Different agencies have special rules regarding signs. Make sure you're following the rules that apply to your trail. In deep snow country, try to locate the post in relatively flat surroundings to reduce the effects of snow creep, which can carry signs down the hill.

Sign Plans

The number and types of signs and reassurance markers should be detailed in a sign plan for the area you are working in. Consistent with the plan, signs and markers should be esthetically appropriate, visible, in useful locations, and well maintained. Install no more signs than necessary.

Spikes or lag screws can be used at the base of the post to improve anchoring (figure 86). Seat the post in the hole and keep it vertical while you drop a few rocks into the hole to secure it. Tamp these rocks with a rockbar or tool handle to jam them into place. Continue to place rocks and dirt in the hole, tamping as you go. Top off the hole with mounded soil to accommodate settling and to prevent water from puddling around the post.

Photo of the side view of how a post is to be installed into the ground entitled 'Signpost Instrallation'. Labeled with text and an arrow: Compressed soil, Anchor bolt, and Rock laid and tamped tight. The hole is labeled: Hole 500 to 600 mm (20 to 24 in) deep.
Figure 86—The key to placing solid posts is to tamp the
rock and soil with a rockbar as you fill the hole.

In rocky areas or very soft soils (such as those next to a turnpike), signposts can be supported by a cairn. Horizontally placed spikes or lag screws should be used at the base for anchors. Chinking the cairn with smaller rocks helps tighten the post against the larger stones. "Anchoring Trail Markers and Signs in Rocky Areas" (Watson 2005) provides instructions for installing signposts without using heavy tools and equipment.

Signs should have holes already drilled so they can be attached to the post. Level each sign and secure it with galvanized lag screws or, better yet, through-bolts that have a bolt head and washer on one side and a washer and nut on the other. Galvanized hardware reduces rust stains on the sign. New wood preservatives like ACQ (alkaline copper quaternary compound) are highly corrosive to aluminum and carbon steel. Use triple-dipped galvanized fasteners. Galvanized washers should be used between the head of the screw and the sign face to reduce the potential for the sign to pull over the screw. In areas where sign theft is a problem, use special theft-prevention hardware.

The bottom edge of signs should be set about 1.5 meters (60 inches) above the tread. The sign's top edge should be 50 millimeters (2 inches) below the top of the post. Where snow loads are a problem, the post can be notched and the signs seated full depth in the post. Treated posts will be susceptible to rotting where they are notched, so they should be spot treated with preservative.

Use caution when mounting signs to trees. The sign should be obvious to travelers and legible from the tread. If signs mounted on trees doesn't meet these conditions, use a post instead. Mount signs to trees with galvanized lag screws and washers, rather than spikes. That way, the sign can be loosened periodically to accommodate tree growth. Leave a gap between the sign and the tree to allow for the growth.

Installing Reassurance Markers

Reassurance markers are used only where the trail is not obvious. If the tread is obvious during the regular use season, these markers aren't needed. Reassurance markers may be helpful if a trail is hard to follow because the tread is indistinct, regularly covered with snow during part of the normal use season, or if weather conditions (such as fog) make the trail hard to distinguish at times. Reassurance markers also are helpful at junctions with nonsystem (informal) trails, or where multiple trails cause confusion.

Place reassurance markers carefully. They should be clearly visible from any point where the trail could be lost. This is a judgment call, often controversial, based on the challenge level served by the trail and the conditions along it. Higher challenge trails need fewer markers; lower challenge trails may need more.

Each marker location should be flagged before installation and checked for visibility in the desired direction of travel. Each location should be marked in both directions (on both sides of the same tree) so there is no question whether or not the marker is official. The marking decisions should be based on traffic traveling in both directions. Be conservative with markers. It's better to improve tread visibility than to rely on markers, except on high-challenge trails where tread frequently may not be visible at all.

The classic reassurance marker is a blaze cut on a tree. The standard Forest Service blaze should always be used to differentiate it from the freeform blazes and antler rubbings that appear on nonsystem trails (figure 87). Cut blazes carefully because a mistake can't be repaired. If a blaze is consistently buried by snow during part of the use season, the blaze can be cut higher on the tree, but not so high that it becomes difficult to locate from the tread. Cut blazes may, on rare occasions, need to be freshened—recut them carefully.

Drawings of trees with blazes and marker tags.
Figure 87—Blaze trees on both sides. Cut the blaze no deeper than
needed for clear visibility. Blazes are no longer cut into
trees in many parts of the country.
Click here for a long description.

Blazes are no longer cut on trees in many parts of the country. Check with your local trail manager to learn what's appropriate. Policies vary across the Nation.

Different types of blazes may be used on some specially designated trails, such as the Appalachian Trail. Blazers (sometimes called marker tags) are used when higher visibility is desired and esthetic considerations are not critical. The most common tags are colored diamonds of plastic or metal, reflective for night use or nonreflective when called for in the trail management plan. Various colors are used. These tags should be mounted on trees using aluminum nails. Allow 12 millimeters (½ inch) or so behind the tag for additional tree growth. Directional arrows, where appropriate, should be placed in a similar fashion. Markers also can be mounted on wooden or fiberglass posts.

Blazers should be checked for continued usefulness. If the tread is more obvious than when these markers were originally installed, consider removing some. If folks are getting lost, restore more visible tread, move existing blazers to more visible locations, or add a few more where they will be most effective. Remove all signs and blazers that don't fit the plan for the area.

Painted blazes are sometimes used. Be absolutely sure to use a template of a size and color specified in your trail management plan. Don't let just anyone start painting blazes.

Cairns are used in open areas where low visibility or snow cover makes it difficult to follow the tread or where the tread is rocky and indistinct. Two or three stones piled one on top of the other—sometimes called rock ducks—are no substitute for cairns and should be scattered at every opportunity. Cairns are similar in construction to rock cribs and consist of circular tiers of stones (figure 88).

Drawings of the side and top views of cairns
Figure 88—Two- or three-stone rock ducks are no
substitute for cairns and should not be built.
Click here for a long description.

Make the base of the cairn wide enough to provide enough batter for stability. In really deep snow country, you may need to add a long guide pole in the center as the cairn is built. If it's appropriate to remove the guide pole during the summer, a pipe can be built into the center of the cairn, allowing the guide pole to be removed easily.

Cairns should be spaced closely enough that the next cairn is visible in either direction from any given cairn during periods of poor visibility (such as dense fog). Cairns should be placed on small rises (not in swales). If cairns are used in areas of large talus, use a 2-meter (6.5- foot) guide pole in the center to distinguish the cairn from other piles of rock. The best time to decide where to place cairns is during a day with poor visibility.

In some settings, guide poles are more effective than cairns. They are most useful in snowfield crossings to keep traffic in the vicinity of the buried trail. Guide poles should be long enough to extend about 2 m (6.5 ft) above the top of the snowpack during the typical season of use. Guide poles should be at least 100 mm (4 in) in diameter. They should be sturdy enough to withstand early season storms before the snow can support them and to withstand pressures from snow creep later in the season. Avoid placing guide poles in avalanche paths. Don't mark trails for winter travel if they cross known avalanche paths.

Guide poles are also used in large meadows where tall grasses make cairns hard to spot, or where there is too little stone for cairns.

Maintaining Signs and Markers

Sign maintenance consists of remounting loose or fallen signs, repairing or replacing signs, and resetting or replacing leaning, damaged, rotting, or missing posts.

If the sign is missing, a replacement sign should be ordered and installed. Consider why the sign is missing. If the sign was stolen, consider using theft-resistant hardware to mount its replacement. If the sign was eaten by wildlife, consider less palatable materials. If weather or natural events munched the sign, consider stronger materials, a different location, or a different system for mounting the signs.

Photo Sign Inventories

Before-and-after photos help document what is happening to signs in the field and how new signs look before the forces of nature (and visitors) resume work. A good sign inventory with photos makes it easier to order replacements for missing or completely trashed signs.

For signs mounted on trees, you may need to loosen the lag screws slightly to give the tree growing room. If the sign is on a post, check to make sure that it is snugly attached. Replace rotting posts. Don't just try to get through "one more season."

Check with your manager for guidelines that will help you decide when signs should be replaced because they have bullet holes, chipped paint, missing or illegible letters, incorrect information, cracked boards, splintered mounting holes, or missing pieces. Consider the consequences of not repairing or replacing deficient signs. Take some photos to help portray the situation.