Silent Trail
Near Goat Mountain, Montana
What's a "Silent Trail?"
One mission of the Society is to help in the planning, development, and maintenance of the Continental Divide Trail as a "silent trail."
A "silent trail" is one that provides enjoyment of a natural environment, free from the noise and hustle and bustle of everyday life. Travel on foot and on horseback is always welcome. Motorized vehicles and mountain bikes may only be used, however, on certain sections of the Trail. This page outlines our views regarding such use.
Motorized Vehicles
A national scenic trail is intended to provide an outdoor experience that offers solitude, challenge, and an appreciation of attractive natural and cultural locations. As provided by law, the basic principle is that "the use of motorized vehicles ... shall be prohibited."
At the present, however,some portions of the CDT are open to motorized vehicles. This is permissible, under the National Trails System Act, in two situations: (1) where the selected route for the Trail is on a "road" or (2) where motorized vehicle use was allowed by administrative regulations at the time the Trail was designated (1978) and continued use "will not substantially interfere with the nature and purposes" of the Trail.
We view the "road" situation to apply to those travel routes that are designated as highways, county roads, or national forest development (or equivalent BLM or NPS) roads. The Trail is sometimes on highways or high-standard gravel roads because there is no other legal right-of-way through blocks of private land. Hiking along such roads is dangerous as well as depressing. The Society has sought to minimize the use of such roads and urges that greater efforts be applied to acquire more attractive off-road rights-of-way.
Roads may also form a temporary portion of the Trail in national forests or public lands until such time as foot trails can be designed and constructed. The Society recognizes the past and ongoing accomplishments of several national forests in relocating sections away from such roads. Continuing this effort is one of our important priorities.
Jeep-type vehicles (as well as ATVs and motorcycles) also commonly employ two-track travelways that should not be considered to be "roads." Such travel, along with off-road vehicle use of trails, can only be accepted where grandfathered -- i.e., where authorized prior to the time of route selection -- and then only if continued use "will not substantially interfere with the nature and purposes" of the Trail.
(According to the Forest Service's Comprehensive Plan,, "the nature and purposes of the CDNST are to provide for high-quality scenic, primitive hiking and horseback riding opportunities and to conserve natural, historic, and cultural resources along the CDNST corridor.")
Several factors come into play in determining whether motorized use interferes "substantially." Traffic that is noisy and speedy, particularly in remote backcountry settings, is especially intrusive and undesirable. On the other hand, the use of an old two-track that sees no more than the occasional rancher's pickup may be acceptable. We have consistently followed these principles in our efforts to influence management of the Trail. Where the conflict is significant, the route should be closed to motorized vehicles or the Trail should be moved to a new location.
Mountain Bikes
Mountain bikes were not in common use until the mid-1980's. As a result, neither the 1981 environmental impact statement nor the 1985 comprehensive management plan for the Continental Divide National Scenic Trail considered their use. The EIS noted impacts "due to increased use by hikers, horseback riders, and pack animals" but made no reference to cycles. The comprehensive management plan recalled, in keeping with the national scenic trails concept as seen in the Appalachian and Pacific Crest Trails, that the Trail should be regarded as a simple facility for the hiker and horseman -- again with no reference to other users. However, when the comprehensive plan was revised in 2009, it provided that bicycle use may be allowed if it will not substantially interfere with the nature and purposes of the CDNST.
As in the case with our sister trails, we consider that the use of mountain bikes does alter the experience of a hiking trail and, in the case of the CDNST, does interfere with its nature and purposes. In judging whether this interference is substantial, several factors need to be taken into account.
Interference with the nature and purposes of the trail is most substantial in areas that are natural, scenic, and undisturbed. We regard any mechanized or motorized use in such areas to be incompatible with the nature and purposes of the trail. Segments that lack significant attributes of this character, with little to prompt the passing hiker to pause and enjoy his or her surroundings, might be opened to bicycles on a case-by-case basis.
We are dedicated to the vision of the original advocates of the Continental Divide National Scenic Trail, who wrote in the Study Report provided to Congress in 1976:
"The trail experience on or near the Divide is an intimate one, for one can walk or ride horseback across vast fields of wildflowers and contemplate a story dating from the dawn of earth's history ... Along the way, the tranquility of the alpine meadows, verdant forests and semi-desert landscape overwhelms everyone who passes that way. The trail would provide the traveler his best encounter with the Continental Divide — its serenity and pure air — and would supply for every trail traveler some of the world's most sublime scenes."
These, we agree, are the characteristics of a Silent Trail.
I
One mission of the Society is to help in the planning, development, and maintenance of the Continental Divide Trail as a "silent trail."
A "silent trail" is one that provides enjoyment of a natural environment, free from the noise and hustle and bustle of everyday life. Travel on foot and on horseback is always welcome. Motorized vehicles and mountain bikes may only be used, however, on certain sections of the Trail. This page outlines our views regarding such use.
Motorized Vehicles
A national scenic trail is intended to provide an outdoor experience that offers solitude, challenge, and an appreciation of attractive natural and cultural locations. As provided by law, the basic principle is that "the use of motorized vehicles ... shall be prohibited."
At the present, however,some portions of the CDT are open to motorized vehicles. This is permissible, under the National Trails System Act, in two situations: (1) where the selected route for the Trail is on a "road" or (2) where motorized vehicle use was allowed by administrative regulations at the time the Trail was designated (1978) and continued use "will not substantially interfere with the nature and purposes" of the Trail.
We view the "road" situation to apply to those travel routes that are designated as highways, county roads, or national forest development (or equivalent BLM or NPS) roads. The Trail is sometimes on highways or high-standard gravel roads because there is no other legal right-of-way through blocks of private land. Hiking along such roads is dangerous as well as depressing. The Society has sought to minimize the use of such roads and urges that greater efforts be applied to acquire more attractive off-road rights-of-way.
Roads may also form a temporary portion of the Trail in national forests or public lands until such time as foot trails can be designed and constructed. The Society recognizes the past and ongoing accomplishments of several national forests in relocating sections away from such roads. Continuing this effort is one of our important priorities.
Jeep-type vehicles (as well as ATVs and motorcycles) also commonly employ two-track travelways that should not be considered to be "roads." Such travel, along with off-road vehicle use of trails, can only be accepted where grandfathered -- i.e., where authorized prior to the time of route selection -- and then only if continued use "will not substantially interfere with the nature and purposes" of the Trail.
(According to the Forest Service's Comprehensive Plan,, "the nature and purposes of the CDNST are to provide for high-quality scenic, primitive hiking and horseback riding opportunities and to conserve natural, historic, and cultural resources along the CDNST corridor.")
Several factors come into play in determining whether motorized use interferes "substantially." Traffic that is noisy and speedy, particularly in remote backcountry settings, is especially intrusive and undesirable. On the other hand, the use of an old two-track that sees no more than the occasional rancher's pickup may be acceptable. We have consistently followed these principles in our efforts to influence management of the Trail. Where the conflict is significant, the route should be closed to motorized vehicles or the Trail should be moved to a new location.
Mountain Bikes
Mountain bikes were not in common use until the mid-1980's. As a result, neither the 1981 environmental impact statement nor the 1985 comprehensive management plan for the Continental Divide National Scenic Trail considered their use. The EIS noted impacts "due to increased use by hikers, horseback riders, and pack animals" but made no reference to cycles. The comprehensive management plan recalled, in keeping with the national scenic trails concept as seen in the Appalachian and Pacific Crest Trails, that the Trail should be regarded as a simple facility for the hiker and horseman -- again with no reference to other users. However, when the comprehensive plan was revised in 2009, it provided that bicycle use may be allowed if it will not substantially interfere with the nature and purposes of the CDNST.
As in the case with our sister trails, we consider that the use of mountain bikes does alter the experience of a hiking trail and, in the case of the CDNST, does interfere with its nature and purposes. In judging whether this interference is substantial, several factors need to be taken into account.
Interference with the nature and purposes of the trail is most substantial in areas that are natural, scenic, and undisturbed. We regard any mechanized or motorized use in such areas to be incompatible with the nature and purposes of the trail. Segments that lack significant attributes of this character, with little to prompt the passing hiker to pause and enjoy his or her surroundings, might be opened to bicycles on a case-by-case basis.
- One factor that should be considered in such a situation is the anticipated level of bike use, which can be addressed through the setting of carrying capacity, monitoring, or other administrative provisions: proximity of access roads and population centers for example, as well as enhanced use resulting from publicity or potential for commercial guiding, may call for evaluation.
- High-speed bicycle travel may not only severely conflict with hikers' and horsemen's enjoyment of the trail, but may present significant risks to user safety as well.
- An objective of a national scenic trail is to provide for the conservation of its natural qualities. The potentials for erosion or other adverse environmental effects resulting from bike use, including impacts to fish and wildlife resources, also need to be taken into account.
We are dedicated to the vision of the original advocates of the Continental Divide National Scenic Trail, who wrote in the Study Report provided to Congress in 1976:
"The trail experience on or near the Divide is an intimate one, for one can walk or ride horseback across vast fields of wildflowers and contemplate a story dating from the dawn of earth's history ... Along the way, the tranquility of the alpine meadows, verdant forests and semi-desert landscape overwhelms everyone who passes that way. The trail would provide the traveler his best encounter with the Continental Divide — its serenity and pure air — and would supply for every trail traveler some of the world's most sublime scenes."
These, we agree, are the characteristics of a Silent Trail.
I