Designing and Building a Foot Trail

by Walt Cook


Walt Cook is a founding board member of ORLT who served on the board for 26 years and donated ORLT’s first conservation easement, protecting 42 acres along the Middle Oconee River. Walt, a retired UGA Forestry School professor and co-founder of the Sandy Creek Nature Center, was head of the Benton MacKaye Trail Association maintenance in Georgia for 5 years, and maintained his own section of the trail for 17 years. He stopped that work in 2014 to become a trail maintainer at the Georgia Botanical Garden in Athens. Walt estimates that in his 48 years of trail building he has built over 100 trails, including private trails, trails for local parks, and a trail at the only Revolutionary battlefield in Georgia. Walt also designed and helped build the 4.1 mile Cook’s Trail, that connects Sandy Creek Nature Center and Sandy Creek Park.



First, a note: The recommendations in this paper are based on the author’s experience over a period of 47 years of designing and building foot trails, totaling many miles in various terrain, in Georgia and South Carolina. Although I have worked with crews of one or more people, most often I worked alone. This essay assumes the reader will do the design and building of the trail by himself or herself.


Reasons for a Trail


A foot trail must have a reason for being. No one builds foot trails merely for the enjoyment of building one, although building a trail can be satisfying in three ways. One, a trail builder, should imagine the future user enjoying a walk or hike on it. Two, most trails, as they are being built, provide a challenge to the builder – getting through or around a physical obstacle. Solving the challenge can be a source of pride to the builder. Three, building a trail requires the builder to be outdoors, usually in an attractive natural environment. One may plan a trail while sitting at a desk and studying a map, but ultimately one must get out on the site, in the fresh air, and away from the noise of the developed word.


So let’s assume there is a reason; the trail will be useful, and used, once it is finished and ready to be walked on. Let’s assume there’s a reason many people enjoy walking on unpaved trails, and will go out of their way to do so.


Another reason for making a foot trail is to introduce people to the natural environment, to ease their reluctance to get into nature. A good trail doesn’t require a person to actually touch nature, or allow nature to touch them. In other words, it will reduce or alleviate their learned fear of the unknown.


A third reason for using a foot trail can be a result of reason number two. New hikers will have learned that the natural environment is not only safe but very interesting and enjoyable for itself. Many people are curious about the unknown, and always wonder what they will see around the next bend. If they find a kind of mushroom they had never seen before, or any unfamiliar plant or rock formation, that discovery is a source of enjoyment that “makes their day”.


A fourth reason to use a foot trail is for physical exercise. The recent restrictions on our normal activities have brought out very visible reasons for walking. Many people are out walking for exercise in their local neighborhoods, (although on paved streets). I will borrow the words on a T-shirt I bought at the Charlie Elliott Wildlife Center, near Mansfield (a great place to hike on all dirt trails). I think the American Hiking Society is probably responsible for the idea. The T-shirt reads:


“HIKING – MOTHER NATURE’S MIRACLE MEDICINE

Refreshing, Rejuvenating, Restorative

Alleviates: Stress, Melancholy, Boredom, Irritability, Sleeplessness, Pallor, Loss of Vitality, Tedium, Listlessness, Discontent, Bad Temper, and Much More.

USE GENEROUSLY”


Design Considerations


So, to begin a trail project, the designer/builder should know who will use the trail, and for what reason. Will the trail be satisfactory for those who want a short walk: an hour or less, or a half day, or a full day, while eating their lunch on a bench, a log or a comfortable rock? Will the user expect to see a major destination such as river, a small canyon, or a waterfall? Or will they be content to follow a seemingly aimless route through an attractive forest, seeing wildflowers and hearing songbirds?


For whatever reason the walker uses the trail, the builder/designer should make the trail safe and ensure that it doesn’t require exceptional physical effort. The hiker should not be expected to climb a rock ledge, or jump across a gully or branch. If the trail is designed to be for the general public, and not specifically for young, athletic people, the trail should be accessible for all ages and conditions, short of those dependent or a walker, or stroller.


Designing the Trail on the Ground


Before tying the first flag or sticking the first wire flag, the trail designer/builder must become familiar with the area to be served by the trail. Know the boundaries of the tract. Are they marked? If not, on private property, walk the property with the owner and have the boundaries pointed out; or better, if there is a legal plat, ask for a copy and mark them yourself with different color flagging than will be used for the trail. The same is true of a publicly owned tract. Do not rely on guesswork for the boundaries. By walking and marking the boundaries yourself, you can see what the surrounding land is like, and check for potential problems if a trail is built.


If the tract is large, 100 acres or more, a good source of information about the topography of the tract and the surrounding area is a USGS contour map and/or a recent aerial photograph. Another source of information may be city, county, or regional planning departments. Those offices may have maps and aerial photos that will aid the designer.


When scouting the interior of the tract, note the locations of desirable features, as well as obstacles to avoid, and flag them. Discuss with the owner any particular items of interest. This is important if the reconnaissance is done during the fall or winter. The owner may be aware of any spring wildflowers that might be seen from the trail, or that should be protected from damage during the establishment of the trail. Some owners may be specifically fond of ferns or other plants and shrubs that the designer might otherwise assume to be sufficiently common to ignore.


As with wildflowers, the existence of historic cemeteries should be noted, both for the desirability of being seen from the trail, and to make sure f the trail construction does not destroy any grave sites. Once, when I worked on a trail through a Revolutionary battlefield, a specialist used Lidar to identify and mark sites that were graves of soldiers who had been buried where they fell, so I could avoid these spots.


Other features to avoid are seasonal seep springs, deep and/or steep gullies, and unusual rock outcrops. Also note potential views of desirable landscape features; this could include notable large trees, as well as trees of an uncommon species. Whatever the item may be, it should be flagged and noted on a sketch map of the tract.


Having become familiar with the boundaries and interior characteristics of the tract, it is time to mark the trail route. While exploring the property, major attractions and problems should have been flagged as important points on the eventual trail route. The location of these features will inform the trail location. An obvious point to begin with, is the location of access to the trail. The point of beginning may be the back door of the owner’s residence. On public land, a provision should be made for a safe parking site for visitors to access the trail itself, or a short connector it.



Flagging the Route


Tying hanging flags on the proposed route is quite possibly the most critical step in making a trail. This is especially true if the labor of physically building the trail will be done by others. The crew is expected and assumed to follow the flags, so mistakes or poor judgement in flagging the route are often difficult to correct. But if the trail will be built by the person that tied the flags, corrections can be made at the time of clearing and raking. In my experience, there has never been a flagged route that was not changed at the time I built the trail. (I have also made corrections on a route flagged by a contracted designer.)


Over the years, I have developed some rules and “rules of thumb”. It has been widely accepted that “rules are made to be broken”, but some rules are more important than others. One such firm rule is to never run an unsurfaced foot trail perpendicular to the contour of the slope for more than a few feet (10 or less). The steeper the slope, the more important the rule. The flagger should observe the pros and cons, then ask herself: Can it be drained both before and after the perpendicular stretch of tread?” Likewise, when routing on a slope, it is usually preferable to make a side hill cut in order to create a nearly flat tread, rather than taking the trail directly up the middle of a ridge, although often a tempting choice. The sidehill route can be drained, but a trail on the ridge, unless it is flat or nearly so, will be difficult to drain, and the result will be an undrainable gully. In any case, do not allow the obvious labor or difficulty of digging on the side hill sway your decision to design the tread on the side hill.


Another rule that is usually best to follow is to run the trail above a large tree on a slope, the larger the tree and/or the steeper the slope, the greater the need to adhere to the rule. The reason for this is that trees, especially hardwood species, tend to have their roots on the downhill side close to the surface and these would need to be cut if the trail was downhill from the tree; trees’ roots on the uphill side are usually not shallow. Actually there is often a small flat area above the base of the tree, wide enough to route a narrow tread that usually requires only a small hill cut.


A good rule to follow is to stay away from the boundaries of the tract. The distance from the boundary will depend somewhat on the terrain and vegetation of the separation, but 100 feet is often a good minimum distance. Visibility is an important consideration. A person walking the trail should not have to lose the feeling of being away from others; likewise, a landowner/resident of the adjoining land does not want to lose privacy in his/her backyard. Don’t forget a vegetative screen may disappear during the winter. The flagger may have to resort to making a switchback to comply with this rule. And if you are satisfied the neighboring land looks wild and unoccupied and thus the trail could come close to the boundary, remember ownership changes, and the new neighbor may develop the land so that any sense or naturalness is lost.


Before getting into the details and problems of switchbacks, a switchback should be defined as many trail users and even some trail designers, use the term incorrectly. If a trail is following up or down slope on a steep hillside, and the hill slope becomes too steep to establish a reasonable tread by making a deep cut in the hillside, a decision is made to reverse the direction of the tread, so that if the trail user has had an uphill to the righthand, and the trail turns sharply to the opposite direction, and the up slope is now on one’s left, that is a switchback. As one approaches the sharp turn, one can see the trail below, and the enticing opportunity for the hiker to take a shortcut (go off the trail so as to save time) is obvious. It is difficult to design a switchback that will discourage the shortcutter. A switchback is usually associated with difficult topography, such as steep hill slopes, but it can also be needed if the route is interrupted by the tract boundary or a water course, or a large, uncrossable gully.


In trail design, switchbacks should be avoided; if possible, use a thicket or other obstacle to guard against shortcutting. An example of the drawbacks of switchbacks used to be found ( before a major re-design) on a section of the Appalachian Trail that ran uphill south from Hogpen Gap. This section of the AT had been designed with so many switchbacks, so close together, that had been short-cutted by hikers, the actual trail had evolved into a long, nearly straight downhill and eroded trail. The re-route was a great improvement, but unfortunately, the eventual re-design to eliminate so many switchbacks also had many unnecessary switchbacks, and these have been shortcutted as well.


Some people incorrectly use the term “switchback” when describing a trail that climbs up a slope in a draw such that the trail grade becomes too steep to continue. The trail then crosses the drain (which may contain a branch) and continues up the slope. In this case, the upslope is on the walker’s right, and after crossing the branch, the upslope is still on the walker’s right. This is not a switchback; it doesn’t invite a shortcut. In this situation, as the trail approaches the crossing, the trail should be guided downward into the stream or drain for a very short distance. This will prevent the stream from leaving its normal course and diverting onto and down the trail, causing a gully to form in the trail.


Floodplains, also known as bottomlands, should be avoided, for two reasons. One, an area is called a floodplain because it gets flooded, which would destroy the trail, or at best cause it to be temporarily closed. Another reason is the alluvial soil found in floodplains does not support much foot traffic. The soil, unless it is sandy, becomes compacted, and the tread is depressed as there is no way to drain it. If the steam is a major river, it may have made its own levee by frequent or annual floods, carrying soil. Coarser particles will drop out if the flood is not major, allowing the soil near the river to accumulate and over the years build its levee several feet higher in elevation than the bottomland farther from the river. A high levee makes a good route for a foot trail; a secondary benefit is in providing the hiker a view of the river. An alternative to a levee trail is to avoid the expected flood by locating the trail in the lower slope of the land adjacent to the bottom.


A word about alignment. Most alignment questions should be answered by the topography, but on strictly flat upland, such as one would find in an old field, the tendency is to route a trail straight. But straight trails tend to be boring, and offer few surprises or an expectation of surprises. On the other hand, a change in direction, not related to topography should not be sudden. Trails do not like corners. Changes in direction should be made in graceful curves. A trail designer friend suggested they should “emulate a bird soaring high above.”


It is good practice to walk the flagged route back to the beginning, as walking back may disclose problems.


Advice on tying flags: When tying flags to denote a final route, or even in the first trial route, only tie flags around tree that are not to be cut or dug out. And don’t tie to a dead branch. Better to tie on a small, live twig; it will have a better chance of flying or moving in a slight breeze, making it easier to be seen. The color of the flag is less important than if it is moving.



Raking and Clearing


Raking and clearing, the physical actions required to make a foot trail can be done with four hand tools. No one of the four is most important, but the first used is the fire rake. It was devised in the early 1930’s by adapting the common cutter used in mowing hay or grain and drawn by a tractor, or more likely a horse or a mule. It has four triangular-shaped teeth fastened to a steel bar and held by a long handle. It is not only used to rake surface leaves to leave a partially bare path, but can cut small roots and vines or tear them out. It is also used to rake smooth the dirt that is torn up by the pulaski (sometimes capitalized, named for the firefighter hero of the big 1920 fire in Idaho). The pulaski is basically a mattock blade with an ax blade on the other side rather that a pic, all in one piece of metal. It is used to dig small saplings’ roots and stumps, larger roots, and rocks. A Pulaski is also used is to cut and dig a sidehill trail, to make a good tread surface.


Two other tools are a hand held pruner and a small (8”) folding saw. Both items are held in a single holster and fastened to one’s belt. The pruner is used to remove side branches extending into the trail space, and roots that refuse to be cut by the fire rake. Whatever branch is too big for the pruner can be sawn by the pocket saw. With patience the saw will remove a limb up to six inches in diameter. Thus, one person can carry all four tools and use whichever is needed at the moment. A chain saw will be needed to remove obstructing fallen logs, on a separate trip or by a separate person. For safety, a chain saw should not be operated by one person working alone. Another tool that may be needed is a swingblade, sometimes called a slingblade, for clearing briers and non-woody vegetation.



One or two persons begin the physical work of making a foot trail by raking and clearing. The person with the rake has the simple job of removing surface leaves from the tread, which is usually a two or three foot wide swath in line with the flags. Of course, it isn’t always as simple as that. In a hardwood forest, there are always dead limbs that must be raked in addition to the leaves. At times, the dead limbs are too big to rake, so the raker must move them off the trail by pulling them or by sawing them into smaller pieces with the folding saw. Anything too big to saw with hand saw must wait for the chain saw.


The raker works with the pruner and handsaw as well as the pulaski. The four tools work as a team – a one-person team, as the work progresses along the line of flags. Any seedling and sapling in the future tread must be removed with the pulaski, digging them in such a way that does not leave a hole in the tread. It may be tempting to merely clip or saw the stem at the ground, but a hardwood species will spout from the cutoff stem, leaving the sprout to be removed by digging by the trail maintainer, a much more difficult job than digging when the sapling is erect. The raker also trims branches that extend into the trail space, typically four feet wide. This is not merely cutting the ends on the limbs; one must trim the branch at it’s junction with the main stem or to a larger branch. Try not to leave stubs so as to make the trail appears as natural as possible. I once was trimming a trail of its protruding branches when a couple walking by rather brusquely asked me what I was doing. I told them I was keeping the branches from hitting hikers in the face, ie, keeping the trail open – they said, “Oh, we thought the trail was always natural.” That was my goal, to make sure the maintenance looked natural.


The raker has the responsibility of following the flagged line, unless he sees a problem with that line. In that instance, if the raker can see a better route, then the raker makes the change, which is usually not major. Of course, when the line goes through a large stumphole, or an immovable rock, the route must be adjusted. The raker has the responsibility to guide the trail across a gully in such a way as to make a safe crossing, rather than go straight down one side and up the other.



Sidehilling


Sidehilling is the descriptive term used to indicate a deep cut and flattening of the tread to provide a good footing for a hiker. A side slope of over five percent usually requires a sidehill cut. But the raker’s judgement can decide when a slope is too steep for an ordinary tread on level ground. Different trail builders have different methods for sidehills, but the following describes my method.


Using the ax blade of the pulaski, cut a vertical slot in the dirt in line with the route and about a foot uphill from the expected center of the tread; this will sever the “rootmat” that contains the fibrous roots of the minor forest flora. If the ground is soft enough, a first pass may also cut many roots close to the surface. Using the mattock blade of the pulaski, chop and pull the loosened dirt away from the upper side that has been marked and partially cut with the ax blade. The raker then removes as much dirt as is loose. On a slight slope, this may suffice to create a flat tread, wide enough to use. On a steep side slope, more cuts may be needed, after the removal of the loosened dirt and roots. Further cutting and digging and removal of annoying roots will eventually provide a good tread. Do not use the excavated dirt to make the tread wider – all that dirt must be discarded down the hill. Sidehilling can be successfully done on hill slopes of 50% to 60% in the Blue Ridge; in the Piedmont, slopes are usually 20% to 40%.


That may seem to be a simple, straightforward activity, although tiring. The un-simple part is when the cutting and digging and raking is interrupted by large roots and/or rocks. Large roots, over three inches diameter, require a decision – to cut or cover. Roots that are left will be a problem as long as the trail is used – they seem to rise to the surface, and they do, due to compaction of the surrounding dirt as well as by frost action. Unless the loss of the root will not severely injure the tree they come from, it is often better to take the time and effort to cut and remove them.


Large rocks present a similar decision, but one that is a problem in a different way. One, unlike roots, trail markers often do not know how big a rock is when it is first discovered. Removing it often depends on how much time and effort one is prepared to expend. But if a rock can be made to wiggle, after a few digs, when pried with a mattock blade, the news is good – it can be removed, with enough patience and effort. But if after several minutes of digging, it doesn’t wiggle, maybe it’s time to 1) ignore it; or 2) move the tread to miss it. Sometimes, the rock may be chipped by the mattock blade to reduce its height to a tolerable level in the tread surface. Sometimes the rock may be induced to split with the mattock. Anyway, a large rock is a challenge. “How about using a prybar” you ask? Answer: “One doesn’t carry a heavy prybar very far from the truck to remove one rock.” Of course, if the rock is removed, the hole it occupied must be filled with something. Start with loose rocks, then fill with dirt, pack it down, and add more dirt. Do the same with stumpholes, if the line of the tread cannot be moved slightly to miss it.


If the flagged route encounters a gully from one to several feet deep, the line of the trail should be altered so as to cross the gully at an angle. Treat the slope down to the bottom of the gully and back out again as you would an ordinary hill slope. The same technique would be used when crossing an old woods road with steep sides.


Maintaining a Dirt Trail


There is no such thing as a maintenance free trail. Side vegetation grows, trees drop dead branches of all sizes, entire trees, dead or alive, fall across the trail. Rain falls on it, and users walk or run on it. This section will look at these factors and show how the maintainer copes with each one.


The first two problems are the most common, and are the easiest to contend with. A trail manager will walk the trail frequently, perhaps once a month, and should carry the two holstered tools on all visits to the trail. The vegetation growing in from the side, or sprouting up in the tread, including non-woody herbaceous “weeds”, can be trimmed as part of the usual visit. Be sure to trim at the junction of the branch and the main body of the plant, or at the next limb that it is joined to. Likewise, the branches and twigs on the tread can be picked up and thrown off the tread. Any branch that is too big to throw can be cut to size with the handheld holstered folding saw. Any that is too big for that saw should be noted and a chainsaw can be assigned to remove it; the same for a tree that has fallen across the trail.


Skip for the moment the problem of water on a dirt trail, and discuss the nature of soil. The soil, unless made up of pure sand, will compact, under the weight of a walker, and more so if the user is a runner. Soil contains a mixture of mineral particles and space; the space is occupied by air and water. The weight of a walker compresses the mineral portion and it replaces much of the space that was air and water. After the first few walkers have used the new trail, this process has compacted the top few inches, and the surface has become firm; most of the effects of the compaction are no longer of serious concern to the maintainer. However, the surface is now showing tree roots and rocks that were left in the original construction, because the soil surface around them has been compacted down below the roots, and they may have to be removed if they are a hinderance to users.


Now, another factor, abrasion, becomes a concern to the maintainer. With each step of a user, the soil particles of the surface of the tread are loosened from the seemingly solid surface. If the particles remain there after becoming loosened, there still is no damage done. But the third factor of deterioration will begin. According to the first principle, water always runs down hill. Once it moves, it also takes with it the particles loosened by abrasion. According to the second principle, the longer the stream of water remains on the trail, its volume and velocity will continue to increase, resulting in more and larger particles moving with the water. The particles themselves will act as abrasives, adding to the amount of soil and larger particles being moved down the trail. Consider that if the trail continues to be used, the abrasion and subsequent erosion will get worse – it will never get better without some serious action to break the steam of water from staying on eroding the tread.


Maintaining the tread can be accomplished by breaking the flow of water down the trail, but only if the original route did not run down a slope perpendicular to the contour. If it did, then the best solution is to move the route of the trail so that it will cross the contours at an angle less, by several degrees, than 90. Assuming the route was properly designed, and assuming the trail has been in use for a season of hiking, the compaction, even without any complications of erosion, the tread will have formed into a slight saucer-shaped cross section. The downhill side of the saucer, or dish, will have formed a slight berm. A rather simple solution is to use the fire rake to dig breaks in the berm at frequent intervals or to eliminate the berm entirely, to let the water escape the shallow dish that holds the stream of water. This works if the dish hasn’t been forming for several seasons, due to ignoring the problem. Using the rake will help prevent further deepening of the dish. For a trail that does have a deeply dished tread, one may need to use the pulaski to provide a larger break in the berm.


Maintenance with Ditches


For trails that are older and have a more serious drainage problem, the tread will need to have a type of ditch/dam dug into it, at an angle to the trail, and hopefully close to a line running perpendicular to the contour. The older version of this diversion is called a water bar. A line on the trail is made to note the location of the water bar. A log, 8 inches or more in diameter, is cut from a live tree, preferably black locust or white oak, and 6-8 feet long. A ditch is dug across the trail about as deep as half the diameter of the log. Place the log in the ditch so it is solidly set. The log must extend a little longer than the ditch on the upper end, but longer at the lower end. Be sure the ditch extends far enough on the downhill end that nothing will plug the exit. The log should be large enough to divert any surface water that is running down the trail. A similar design is to place relatively flat stones on edge into the trench instead of a log, and allow the stones or rocks to extend above the tread surface, overlapping in a shingle fashion to divert the water that is running down the trail; this method will be more permanent, but depends on the availability of suitable rocks close enough to carry to the site.


Another style of water diversion is similar to the water bar, but without the log or rocks. Most people call it a dip. Locate a line that, like the water bar, is close to being perpendicular to the contour, and dig a ditch about 6 inches deep on a new trail. If the trail already has a saucer-shaped bottom, the ditch should not be as deep. Throw all the dirt removed from the ditch to a pile three feet downslope from the ditch, to form a pile roughly parallel to the ditch; it will be called the “hump.” Measure six feet up the trail from the ditch to mark the top of the approach wedge. Begin the removal of the dirt from zero at the top of the wedge to the bottom of the wedge at the ditch. All that dirt is added to the hump, compacting it as the hump grows. Taper the lower end of it down to the unchanged tread. The end result of moving the dirt and making the hump is an S-shaped surface by smoothing out the bottom and the top of the hump. When finished, the top of the hump is one foot higher than the bottom of the ditch.


The entire structure serves two purposes: to divert water that may be running down the trail, and to cause no discomfort to the users. The uphill walkers will not be “stepping into a hole” (which is hard on one’s back) and the downhill walkers will not trip over the hump. I “interviewed” two people who had just walked over a segment of trail about how they liked the new drains I had just finished. Both walkers said they didn’t know there were drains in the trail. Apparently they were not paying attention to the trail, because the drips were quite visible.


Both types of diversions must be long enough and wide enough to work properly. An exit ditch has to be wide and needs to continue well beyond the trail, especially in rolling topography. In mountainous land, the exit is obvious, as the surface drops quickly down the slope of the mountain. In less steep land, if the exit is too narrow or too short, a simple dead twig can lodge across the narrow ditch, and leaves or pine straw will be caught by the dead twig, and a whole series of forest floor debris will get caught and build into a dam. The running water from the trail will be slowed to the point it will cause the stream to drop part of all its load of soil, which then becomes sediment, which increases the effects of the dam.


One problem with a water bar is the relatively short life of the log. If the log is pine or poplar, and the sapwood is still most of the wood, the log will be quite useless in a few years. In the case of the dip, the best structure depends on following the dimensions carefully. If a person that is unfamiliar with the structure and doesn’t know the importance of the dimensions, the approach from the upper end becomes incomplete, and/or the hump is too close to the bottom ditch; in either case the comfort to the walker is diminished. In one memorable case, a person on the organized crew dug a ditch perpendicular to the trail – a twisted ankle waiting for the wrong step. I asked the man to remake the dip from the beginning.


Whichever design one uses, the drain needs to be cleaned annually or semi-annually. After leaf-fall in a hardwood forest, the exits need to be raked, the breaks in the berms need to be renewed, and exposed roots need to be removed. Shortcuts on switchbacks need to be blocked and the switchback needs to be re-shaped. If the trail is open to runners, the shape of the drains need to be renewed; rake the bottoms and re-build the humps.


Trail maintenance never ends.