Shoshone National Forest Travel Plan Comments

North Fork of Pogo Agie River, Cirque of the Towers, Wind River Range, Shoshone National Forest, Wyoming. Photo George Wuerthner

The Shoshone National Forest lies directly east and south of Yellowstone National Park. It contains some of the most important wildlife habitat in the country, including significant numbers of elk, mule deer, bighorn sheep, moose, black and grizzly bear, plus wolves.  It also includes some of the most stunning scenic landscapes in the West, including the Wind River Range, Absaroka Mountains and Beartooth Mountains.

Although much of the forest is designated wilderness, there are large areas of roadless lands that should remain closed to motorized and mechanical travel. Below are some comments sent to the forest.  You try sending your own comments to this address:

ORV use can impact watersheds, disturb wildlife, and conflict with other recreational users. Photo George Wuerthner

Mark Foster, SNF Environmental Coordinator
Attention: Shoshone NF Travel Management Planning Project
Shoshone National Forest
808 Meadow Lane Avenue
Cody, Wyoming 82414 


Dear Mark:

I am sending these as my comments on the Shoshone NF Travel Plan. Could you make sure they wind up in the appropriate comment file. Thank you.

The following are general and specific comments regarding the Shoshone NF travel plan.

I published the book, “Thrillcraft: The Environmental Impacts of Motorized Recreation.” I suggest the FS get a copy and review the various chapters.

First, some general comments.

The Shoshone NF is one of the premier wildlife forests in the United States. And it is also part of the larger Greater Yellowstone Ecosystem. Protecting these wildlife and ecosystem values should be a priority. In other words, this is not just any landscape, but a very special and unique landscape even from a global perspective.

There is abundant evidence that human activities can disturb wildlife and in essence “remove” habitat from use. And the more distances traveled, and the more acre influenced, the greater impact on wildlife.

North Absaroka Wilderness, Shoshone National Forest, borders Yellowstone NP on the east. Photo George Wuerthner 

With regards to any mechanical access, the Forest Service must consider that ever-evolving technological advances are increasing the range and ability to traverse more difficult terrain by any vehicle or machine, including mountain bikes. And we have no idea what “new” access will be created in the future. Maybe personal jet packs or whatever. The point is that the Travel Management Plan should emphasize limits on all human mechanical access in any areas with important ecological, wildlife, and other values.

Even though each new use in and of itself may seem insignificant, it is death by a thousand cuts. The cumulative impact is greater. In particular, as new technology creates the ability to travel further, there is a tendency to expand trail use.. At what point does this collective “access”  become “excess?”

As a basic starting point, the Shoshone NF should restrict access to all roadless lands on the forest. These lands are critical to the “whole” and the whole is the ecological integrity of the Greater Yellowstone Ecosystem. We know from numerous studies that roadless areas provide the best habitat for fisheries and wildlife. A good overview of the impacts of roads on resource values is Frissell and Trumbulak Review of Ecological Effects of Roads on Terrestrial and Aquatic Communities. This should be required reading by all FS administrators.

Elk avoid area with heavy mechanical use, and this use can essentially displace elk from high quality habitat. Photo George Wuerthner 

For instance, one study (Effects of Off-Road Recreation On Elk and Mule Deer Summary of Wisdom et al Studies) found that elk were pushed up to nearly a mile on either side of a trail by mountain bike and ORV use. Hikers had an impact as well but affected a narrower corridor. Given that many mountain valleys are seldom more than a mile wide, this could effectively preclude use by elk in many areas.

There are social issues as well. Motorized users can displace non-motorized users from trails or routes. Photo George Wuerthner 

For instance, one study of radio-collared elk found: “The probability of flight varied according to distance from the disruptor.  When within 100 yards of any of the four disruptors the probability of flight was roughly equal. However, as the distances increased those probabilities spread out. At 500 meters from a hiker, there was basically zero flight response. To achieve the same zero flight response the elk needed to be 750 meters from the equestrians and 1500 meters from both ATVs and mountain bikes.”

Because mechanical access allows a person to travel farther in a day, the potential displacement of wildlife is greater–all other things being equal.  Photo George Wuerthner 

The takeaway from this study:  “Elk flee 2 times as far from equestrians than from hikers and three times farther from mountain bikes and ATV’s than from hikers, and they’re running faster. Hence, the argument that mountain bikes cause LESS disruption than hikers because they’re here and gone quickly isn’t valid based on study data. In fact, we could make the argument that the sudden, intense scare from rapidly moving mountain bikes is the cause for their greater displacement.”

Another study (Reproductive Success of Elk Following Disturbance By Humans During Calving Season) found that “reproductive success of elk following disturbance by humans during calving seasons in central colorado. They reported a significant drop in reproductive success compared to an undisturbed control group.”

Moose reacted more strongly to mountain bikers and motorized vehicles. Photo George Wuerthner 

A study in BC (Relative effects of recreational activities on a temperate terrestrial wildlife assemblage) is particularly germane to the Shoshone NF. The study concluded that “Across 13 species, only two negative associations between recreational activities and wildlife detections were observed at weekly scales: mountain biking on moose and grizzly bears. However, finer-scale analysis showed that all species avoided humans on trails, with avoidance strongest for mountain biking and motorized vehicles”

A review of recreation impacts in general (Effects of Recreation on Animals Revealed as Widespread through a Global Systematic Review) concluded that:” Although publication rates are low and knowledge gaps remain, the evidence was clear with over 93% of reviewed articles documenting at least one effect of recreation on animals, the majority of which (59%) were classified as negative effects.”

The highest mortality for grizzly bears in Canada is associated with roads and routes accessible by mechanical vehicles. Almost all grizzlies are killed near roads. Photo George Wuerthner 

A particularly germane study to the Shoshone NF due to the presence of grizzly bears was done in BC. The study (Effects of roads and motorized human access on grizzly bear populations in British Columbia and Alberta, Canada)” We found that motorized access affected grizzly bears at the individual and population levels through effects on bears’ habitat use, home range selection, movements, population fragmentation, survival, and reproductive rates that ultimately were reflected in population density, trend, and conservation status.”

They noted: “In areas with human–bear overlap, a large majority of grizzly bears over the age of 2 are eventually killed by people and almost all are killed near roads (shot, not hit by vehicles). Studies from across west-central North America report that humans cause between 77% and 90% of grizzly bear mortalities.” This suggests that limiting access by any mechanical means would contribute to greater grizzly bear survival.

ORV trails and routes are proliferating in the Union Pass area that lies between the Wind River and Gros Ventre Ranges. Photo George Wuerthner

However, it is not just direct mortality. The disturbance and displacement of bears from important habitat also impact bears. The BC study found: “Consequently, road avoidance remains difficult to discern from survival in the absence of a manipulative or before–after study (see below for more on this topic). Nevertheless, on average it appears that bears avoid roads with vehicular traffic…”

Mountain bikes, especially as E bikes become more common, can travel a much greater distance in a day than hikers, and thus their impact on wildlife is greater. Photo George Wuerthner 

Though all human access potentially can disturb wildlife, the greater distance traveled by mechanical access must be considered. Research done in Utah on Antelope Island emphasizes this point. Taylor and Knight (2003) investigated the interactions of wildlife and trail users (hikers and mountain bikers) at Antelope Island State Park in Utah. A hidden observer using an optical rangefinder recorded bison, mule deer, and pronghorn antelope response to an assistant who hiked or biked a section of trail. The observer then measured wildlife reactions, including alert distance, flight response, flight distance, distance fled, and distance from trail. Observations revealed that 70 percent of animals located within 330 feet (100 m) of a trail were likely to flee when a trail user passed, and that wildlife exhibited statistically similar responses to mountain biking and hiking. Wildlife reacted more strongly to off-trail recreationists, suggesting that visitors should stay on trails to reduce wildlife disturbance. While Taylor and Knight found no biological justification for managing mountain biking any differently than hiking, they note that bikers cover more ground in a given time period than hikers and thus can potentially disturb more wildlife per unit time.

Speed of travel also influence the impact of any activity. Mountain bikes, and other mechanical uses can negatively impact other recreational users. While this is not an ecological impact, it is a social impact. Photo George Wuerthner 

Speed of travel can affect grizzly bears negatively. A study in Banff found: “Park staff noted that hikers were far more numerous than mountain bikers on the trail, but that the number of encounters between bikers and bears was disproportionately high…. Herrero and Herrero concluded that mountain bikers travel faster, more quietly, and with closer attention to the tread than hikers, all attributes that limit reaction time for bears and bikers, and increases the likelihood of sub-fifty meter encounters.”

Here a dirt biker is traveling on a closed trail. Both illegal use of trails as well as expansion of trail systems leading to habitat fragmentation are a major problem with all mechanical access. Photo George Wuerthner

A social issue that the FS must consider is the tendency of people utilizing mechanical access to create new “user” trails and routes. Indeed, a study in Colorado found that motorized users regularly went into closed areas. Mountain bikers also are known for their “rogue” behavior, ignoring trail closures or simply expanding and creating new trails that agencies then often legalize. The FS should immediately close any user trails and put in effective barriers and law enforcement.  As the authors of How formal and informal mountain biking trails result in the reduction, degradation and fragmentation of endangered urban forest remnants expansion of trails and routes fragment habitat. “This study found that formal and informal mountain bike trails can differ in how they reduce, degrade and fragment urban forest remnants. These differences were, in part, a result of the much greater spatial proliferation, and therefore,fragmentation capacity of informal trails that formed dense, geometrically-complex networks that cumulatively resulted in a greater loss of forest than formal trails.”

Snowmobiles can travel into ares in winter on snow that is essentially inaccessible in summer and impact species from bighorn sheep to wolverine. Photo George Wuerthner 

Special attention must be given to winter travel use since unlike summer travel, winter snowmobile use can disperse more widely across the landscape. A study of wolverine (Wolverines in winter: indirect habitat loss and functional responses to backcountry recreation) concluded that recreation. “Motorized recreation occurred at higher intensity across a larger footprint than non-motorized recreation in most wolverine home ranges. Wolverines avoided areas of both motorized and non-motorized winter recreation with off-road recreation eliciting a stronger response than road-based recreation.”

The Shoshone NF should give consideration to how climate change might affect backcountry winter recreation. The authors of the wolverine study speculate that “potential for backcountry winter recreation to affect wolverines may increase under climate change if reduced snow pack concentrates winter recreationists and wolverines in the future.”

Mechanical users are more likely to create multiple trails and add to sedimentation, destruction of plant communities and wildlife habitat. Photo George Wuerthner 

Other impacts associated with roads include chronic sedimentation that impacts fisheries. The literature on this is overwhelming. The more roads, the more sediments in aquatic ecosystems. Frissell and Trumbulack mentioned above have substantial evidence for this impact. I am not going to repeat it here, other than to note that given the important fisheries found on the Shoshone Forest, in particular, critical cutthroat trout habitat, that any reduction in road use and restoration of roads should be a priority. This includes restoring the road lens to the former slope, since disruption of the slope allows “subsurface” water to “leak” on road beds, including flows, and thus erosion.

Carter Mountain, Absaroka Mountains along Greybull River,  Shoshone NF, Wyoming. Photo George Wuerthner 

The review by the USGS (Environmental Effects of Off-Highway Vehicles on Bureau of Land Management Lands: A Literature Synthesis, Annotated Bibliographies, Extensive Bibliographies, and Internet Resources) Even dust from roads can be a problem. The authors stated: “Where the slope is a factor, the extensive networks of OHV routes proliferating across landscapes can serve as conduits that direct or alter the direction of surface flows. These conduits may be eroded to form gullies that channel dislodged sediments and contaminants into aquatic ecosystems. Water quality also is adversely affected by OHV-raised dust that settles into aquatic systems.”

Pilot Peak along the Clark Fork of the Yellowstone, Shoshone NF, Wyoming. Photo George Wuerthner 

One other area to consider is how mechanical access impacts non-mechanical recreationalists. In general, mountain bikes, ORVs, snowmobiles, and dirt bikes have a greater negative impact on hikers, xc skiers, and horse users than hikes, xc skiers and horse users have on mechanical users. To the degree possible the FS should strive to separate these uses. That includes use by mountain bikes on hiker/horse trails.

Wyoming High Lakes Wilderness Study Area. Shoshone NF. Photo George Wuerthner

Specific areas that the FS should consider in the Travel Plan should be permanent protection and closure to all mechanical use in the Clark Fork Wild and Scenic Corridor, Wyoming High Lakes Wilderness Study Roadless Area, Durior, Line Creek Plateau roadless area. The Union Pass area deserves special attention as ORV roads are proliferation in that area.  No expansion of road or trail access should be permitted, and the decommissioning of roads should be the focus of the Travel Plan.

The bottom line is that the Shoshone National Forest should be managing for what it does best–which is to produce outstanding wildlife habitat, intact and expansive wildlands, and functioning ecosystems. All other uses, including recreational use, should be subservient to preserving these primary functions.

Thank you.

George Wuerthner



  1. Robert Hoskins Avatar
    Robert Hoskins


    Thanks much for this column. As a Dubois resident and horseman for more than two decades, I’ve been horrified by the exponential increase of ATVs and UTVs on the Wind River District of the Shoshone National Forest, especially over the last 4 years, beginning with the 2017 Eclipse and lately exacerbated by the pandemic, with everyone from everywhere coming here to get away from where they are, making quite a mess of things.

    The main consequence: the frontcountry of the District is now an industrial park and an ecological sacrifice zone–with the Forest’s blessing.

    Another consequence: hikers, skiers, and equestrians are being squeezed out of the front country by ATV/OSVs: by their numbers, their noise, their pollution, and their extensive damage to the land.

    I’d say more but I’m the middle of writing my own comments on the various Forest proposals for expanded motorized use (comments are due to the Forest by the 18th), with my main focus on the Forest’s determination to run a loop road through the very steep Warm Spring Mountain canyon, probably the only relatively pristine place left in the frontcountry. It’s a stunningly beautiful place, not to mention prime grizzly, wolf, moose, elk, peregrine, and golden eagle habitat. It’s also a critical trout fishery.

    Another feature of Warm Spring Creek is that its heated by residual volcanic activity by virtue of being in the Greater Yellowstone. Not only the creek but also the Wind River, into which the creek flows, remain ice free for 10 miles downstream. This is one of the most unique geological features of the District.

    Thanks again.

    Best, Robert

  2. Robert Hitchcock Avatar
    Robert Hitchcock

    The Shoshone is an anti wildlife Forest managing a priceless portion of the Greater Yellowstone Ecosystem. The year I was run out of the wildlife shop on the Wind River District, all of the district biologists were “purged”. Whole heartedly support “get the cut out” or leave. A forester’s feudal barony.

    1. Ralph Maughan Avatar
      Ralph Maughan


      Please tell us what happened . . . more detail.

  3. Maggie Frazier Avatar
    Maggie Frazier

    I’ve commented many times regarding these “proposals”. Frankly, if riding an ATV/OSV floats your boat then do it in an area meant for that kind of noise & destruction! I can imagine being on a horse in an area like that & having them come upon you. In fact, I dont have to imagine – I remember what its like being on a trail being confronted with several of them. Its intimidating & can be dangerous depending on how quiet & confident your horse is & whether the people on the ATVs know enough to stop & shut them off.
    To allow that kind of “recreational activity” in these pristine places is just wrong.

    1. ROBERT HOSKINS Avatar


      Being on horseback in an area open to ATVs can be challenging and often dangerous. Most of us who have around horses for a long time know that you can train horses to tolerate motor vehicles, but no matter how much training you give them, any one encounter can “freak” them out, with consequences impossible to predict.

      Also, each horse has its own disposition, its own personality, and each will present different levels of tolerance for scary things. My 7 year old Tennessee Walker is the easiest going horse you’ll even meet, and I often ride him on the highway just to keep him in training with motor vehicles. However, even then, he hates convoys of vehicles and may spook when the 5th or 6th vehicle passes. Also, big trucks have a whine from the airflow that he just doesn’t like, and he may spook. We’ve been together since he was born and he trusts me, so it’s relatively easy to calm him down.

      However, my 18 year old Kentucky Gaited Horse thinks ATVs are moose, which he fears from an old moose spook years before I got him, and so he almost always spooks strongly around ATVs, so much so that I will only allow experienced riders to ride him.

      Some ATVers are good around horses, mostly locals, but out of town tourists are not. In the end, it’s best that horses and vehicles remain separated. (Same with mountain bikes). Problem is, in the front country of the Wind River District, that’s almost impossible to do. Sometimes we can get off the trail up or down and away from the vehicles, sometime we can’t. This problem is one the Forest doesn’t seem to worry about. After all, equestrian activities are inherently dangerous ones. The riders risk, and all that.

      Of course, once we get into wilderness, we only have to worry about natural spook producers.


  4. Immer Treue Avatar
    Immer Treue

    Horses and mountain bikes don’t mix well at all.


George Wuerthner is an ecologist and writer who has published 38 books on various topics related to environmental and natural history. He has visited over 400 designated wilderness areas and over 200 national park units.

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George Wuerthner