Impacts of Mountain Biking

Mountain Biking is a significant threat to our wildlands—both in designated preserves like national parks, wilderness areas, and the like, but also Wilderness Study Areas (WSA) and roadless lands that may potentially be given Congressional protection under the 1964 Wilderness Act.

Wilderness designation is one of the best ways to protect biodiversity, watersheds, wildlife habitat, and natural ecological processes. And in this day of climate change, protecting forests, shrublands, deserts, and grasslands in our national wilderness system is also one of the best ways to store carbon.

Lest we forget, there is a finite amount of public land that can qualify for wilderness designation. If we must err on one side or the other, we ought to err on the side of protecting our wildlands heritage.

It is important to note that recreation is not the same as conservation. In any dispute about whether to increase recreational use/access or place limits on recreation, protection of wildlife and wildlands should always receive top priority.

One of the philosophical values of wilderness is the idea of restraint. When we designate a wilderness area, we as a society are asserting that nature and natural processes have priority, and we accept limits on ourselves. It is a lesson that is increasingly important for all to learn in an age of climate change, population growth, biodiversity loss, and other major environmental issues.

In a world filled with such vexing and overwhelming issues, worrying about bicycles on trails can seem trivial and inconsequential. But it’s important to note that bicycles and other mechanical conveyances, and the lack of commitment to personal restraint that it can foster is indicative of the broader challenges facing society. Namely, how do we live on this planet without destroying it? Self-control and restraint will be critical to our future.


The Colorado Parks and Wildlife Department has documented over 33,000 miles of trails in Colorado already, and this doesn’t include thousands of miles of low traffic natural surface roads which are perfectly suitable for mountain bike use. Today only 8 percent of the National Forest acreage in Colorado lies beyond one mile of a roadway (only 4 percent for BLM lands). More recreational access and more miles of trails pose severe threats to wildlife security.

On our national forest system alone, there are more than 400,000 miles of roads. Habitat fragmentation is significant. The opportunity to protect roadless lands as wilderness is shrinking every day.

Increasingly I believe mountain biking is the greatest single threat to wildlife habitat integrity and new wilderness classifications. I’m not the only one. There is a growing number of public lands advocates who see mountain biking, especially the growing network of new trails as a threat. For instance, in a recent overview of mountain biking in Colorado, the Colorado chapter of Backcountry Hunters and Anglers concluded: “the construction and use of new trail type come at a cost: to wildlife habitat and the health of public lands in general. New trail development is perhaps the greatest threat to wildlife in Colorado today.”

There are plenty of mountain bikers who put protecting wildlands as the priority, and their recreational use second. However, almost universally mountain biking organizations oppose new wilderness designation if they pose any restrictions or limits on trail use or new trail creation. Indeed, there is even a sub-set of mountain bikers who support mountain biking in existing wilderness areas. They have succeeded in getting some of the most anti-environmental members of Congress to introduce the Human-Powered Travel in Wilderness Areas Act. While many oppose mountain bikes in Wilderness Areas (even the International Mountain Biking Association) as well as many others, expanding mountain bike use does and can thwart enlargement of our wilderness system.


Mechanical transport, which includes mountain bikes, is expressly prohibited in designated wilderness. Therefore, new mountain biking trails built in proposed wilderness are a threat to classification under the 1964 Wilderness Act.

Many mountain biking organizations know this and specifically, promote new trails and/or use of existing trails in proposed wilderness areas to create an anti-wilderness constituency and make it politically more difficult to classify these critical wildlands as new wilderness areas.

This strategy has been implemented in the Lionhead Proposed Wilderness, Gallatin Range Proposed Wilderness, Big Snowy Mountains Proposed Wilderness in Montana. The same idea has been used to establish mountain biking in the Palisade Wilderness Study Area on Wyoming’s Bridger Teton National Forest.

Similar strategies were used to reduce the size and configuration of the Boulder-White Cloud Mountains WSA in Idaho, which resulted in the split up of one of the largest unprotected roadless areas in the lower 48 states into three separate and smaller wilderness areas.

We see the same pattern on public lands throughout the country.


Mountain bikes pose a threat for four major reasons.

First, there is the tendency for some mountain bikers to create new “rogue” trails. Second, the increasing mechanization of mountain bikes, including now electric bikes, dramatically expands the terrain and distances that can be accessed by a bike. Third, there is a culture among many mountain bikers that glorifies thrills, speed, and the “conquest” of natural barriers. Fourth, there is a growing body of research that demonstrates that mountain bikes have significant impacts on wildlife.

Despite the issues, most large conservation groups have been slow or loath to criticize mountain biking and its culture. Indeed, many groups are actively working with mountain biking organizations to expand the trail miles and impacts to proposed and existing wilderness study areas.

For instance, the Gallatin Forest Partnership in Montana which includes Greater Yellowstone Coalition, Montana Wilderness Association, The Wilderness Society and Winter Wildlands among others proposes “wildlife management area” designation for a portion of the Congressional designated Hyalite Porcupine Buffalohorn WSA in the Gallatin Range over classification as federal wilderness. This compromise is proposed largely to appease mountain biking interests even though more than 2/3 of the trails on the Custer Gallatin National Forest are open to mountain biking.


I wrote a book on Thrillcraft, looking at the ecological impacts of motorized recreation. and

During my research for that book, I found that many of the effects and cultural attributes reported for motorized recreation applied to mountain biking as well.

One of the similarities is the “outlaw mentality” among many motorized abusers of the land, and the same attitude seems to permeate many mountain bikers as well.

For instance, a study in Georgia documented that of the 59 routes surveyed in the Chattahoochee NF, illegal ORV use occurred on 67 %, including designated wilderness and trails restricted to pedestrians.

Another study conducted in Colorado on behalf of Colorado Coalition for Responsible ORV Riding found that even though most thrillcraft enthusiasts understood that they should not stray from designated trails, more than two-thirds admitted they go off-trail occasionally, and 15-20% admitted they regularly rode off legal routes.

There is a considerable sub-set of mountain bikers who are principally concerned with their recreational opportunities above all else. Many even feel a sense of entitlement not unlike the same feeling expressed by many in motorized recreational circles who believe if it’s public land, they have a “right” to access it. Indeed, one of the main justifications mountain bikers use to placate opponents is to argue they help maintain trails, never once realizing that there may already be too many trails and recreational access fragmenting our public lands.

To most mountain bikers, there can never be too many trails.  In the past, most of the rogue and illegal trail construction was done by motorized thrillcraft users, but today the dominant source of illegal trail and new trail construction comes from mountain bikers.

A report issued by the Colorado Backcountry Hunters and Anglers (BHA) in southwest Colorado, around Durango, illegal trails are vexing land managers and wildlife officials, who have struggled with reining in the longstanding, escalating problem. “We’re not talking small connector trails,” said Shannon Borders, spokeswoman for the Bureau of Land Management. “We’re talking miles of illegally built trails.”

Tyler Fouss, a BLM law enforcement ranger, said the trails appear to be mostly constructed and used by mountain bikers. The BLM and other agencies treat the illegally built trails as a criminal case of trespass, but it’s tough to find perpetrators. Since 2015, no one has been caught in connection with building illegal routes.

In an NPR report about mountain biking on New Hampshire’s White Mountain National Forest Jody Chinchen, District Trails Manager on the Pemigewasset Ranger District showed the reporter a new “illegal” trail that she says is “17 miles” long.

The NPR reporter notes that Chinchen calls these trails incidental trails… user-created trails… non-network trails… what she calls bureaucratic euphemisms for what they are: trails that got built on federal land without permission. Chinchen estimated there are about 35 or 40 miles of these illegal trails just in her district of the National Forest.

Many federal agencies unable to stop or thwart illegal trail building eventually try to appease mountain bikers by making previously illegally constructed trails part of the official trail system.

For instance, for twenty years, the Wenatchee National Forest played a cat and mouse exercise with illegal mountain bike trail builders. The forest would destroy the illicit trail, and the mountain bikers would rebuild it. Finally, after twenty years, the Forest Service is making the path a part of its official trail system.

The Helena Lewis and Clark National Forest in Montana has proposed creating new mountain biking trails and legalizing rogue trails in the Elkhorn Mountain Wildlife Management Area. This is a typical response of the agencies to illegal trail construction. They often authorize the trails and add them to the agency trail system, even though there was no environmental review of the impacts on wildlife and other recreaitonists.

Increasingly the Forest Service is using “Categorical Exclusions” (CE) that to approve new trail construction and avoid environmental review by the National Environmental Policy Act designed to articulate impacts. CE is being used by the Helena and Lewis and Clark National Forest along the Continental Divide Trail, and by the Willamette National Forest for creation of new mountain bike trails in the 157,000 acre Oregon Cascades National Recreation Area, an area proposed for wilderness designation, in part, because it is the largest unprotected roadless area in the Oregon Cascades.

One of the environmental impacts that is ignored when a CE is used to approve new trail construction is the potential impact on wilderness designation.


Back in the 1980s, while living in Missoula, Montana, I rode some of the first proto types for mountain bikes. These were clunky old bike frames with large tires which we rode primarily on old logging roads. They were also good on city streets because you wind up fewer flat tires from glass or other road hazards.

Over time, the bike frames were constructed out of lighter materials like carbon fiber, new braking systems, lower gears for hill climbing, adjustable seats, and other modifications significantly increased the speed, and ability to travel rough trails or off trails entirely. With the advent of snow bikes and e-bikes (electric bikes), the season of use has expanded as well as the distances that can be traveled in a single day.

The growing mechanization of mountain bikes and the “convergent” evolution of bike design, especially the advent of electric motors makes them increasingly like dirt bikes.

Due to these improvements, it is reasonable for a mountain biker to cover 20-30 miles in two or three hours. By contrast, all but the fittest hiker is going to have trouble traveling even 20 miles in an entire day. The ability to travel farther and faster, “shrinks” wildlands. That is why mountain bikers continuously advocate for more trails and routes.

One of the problems with the mechanical improvements of mountain bikes over the years has been a greater ecological footprint. The distance one can travel, and the places one can access has increased tremendously. This means mountain bikers “chew up” trails and landscapes and the potential for displacement of wildlife is vastly amplified.

A hiker’s speed doesn’t’ appreciably increase year after year, and as a result, a hiker can experience the same trail over and over without becoming “bored” with the hike. However, the motivation for many mountain bikers is the thrill of speed and risk combined with “bragging” rights. This motivation leads to a significant “desire” to increase the number of miles traveled as well as the demand for new trails.


All of this modification is creating more and more conflicts with other recreational users as well as wildlife. Although the research that explicitly targets mountain bikes is in its infancy, what we do know is disconcerting.  There is a “zone of influence” where recreational use can displace wildlife or reduce the habitat quality.

It is critical to note that even hiking can adversely impact wildlife. But the speed and greater distances that the mechanical advantage mountain bikes confer substantially increases those impacts. A good overview of mountain biking studies can be found here.

Although explicitly looking at the effects of roads on wildlife, many of the same conclusions would apply to trails. Effects of Roads on Animal Abundance: an Empirical Review and Synthesis Another study by biologist Barrie Gilbert– Motorized Access on Montana’s Rocky Mountain Front: A synthesis of scientific literature offers useful insights that apply equally to non-motorized mountain biking.

In a review of mountain biking and wildlife impacts, authors Jeff Marion and Jeremy Wimpey published an assessment, “Environmental Impacts of Mountain Biking: Science Review and Best Practices. In that paper they state: “Trails and trail uses can also affect wildlife. Trails may degrade or fragment wildlife habitat, and can also alter the activities of nearby animals, causing avoidance behavior in some and food-related attraction behavior in others. While most forms of trail impact are limited to a narrow trail corridor, disturbance of wildlife can extend considerably further into natural landscapes.”

According to a recent report by the Colorado Backcountry Hunters and Anglers (BHA)  “Impacts of Off-Road Recreation on Public Lands Habitat” “Wildlife habitat in Colorado is being significantly impacted by the proliferation of mechanized (i.e., mountain bike) and motorized (ATV/OHV) trails on public lands. Sportsmen and wildlife managers are finding that elk hunting opportunities, in particular, are being compromised by trail development in many parts of the state.”

Research comparing the effect of hikers, horse riders, and thrillcraft (mountain bikes and ORVs) on elk flight demonstrates significant differences in impact to wildlife. Hikers can clear a swath of disturbed animals 1/2-mile wide, especially if they have a dog.  Equestrians may impact a swath 3/4th-to-1 mile wide, and ATV’s and mountain bikes clear a swath a full 2 miles wide!  Grizzly bears show similar avoidance for roads and heavily used trails.

Many mountain valleys are not more than two miles wide, so essentially if there is significant mountain biking activity, it can preclude wildlife usage of that area.

Furthermore, the flight response of elk is 15% faster from mountain bikes in comparison to hikers and equestrians.

In another study of human disturbance of elk calving grounds, found that an average of 10 disturbances/cow above ambient levels, the elk herd showed no growth. Their results support maintaining disturbance-free areas from all human entry for elk during parturitional periods.

The BHA mountain biking research noted that former Colorado Parks and Wildlife District Wildlife Manager, Jim Haskins reported “New mountain bike [trail] construction will likely result in permanent habitat fragmentation. Habitat fragmentation impedes the movement of wildlife across landscapes. Looped trails may create islands of habitat that may be avoided entirely by wildlife.”

A Montana study of mechanical Off-Road use found that elk habitat effectiveness was reduced by 25% with a density of 1 mile of trail per square mile.

In an article in Mountain Journal, Todd Wilkinson interviewed retired grizzly bear expert Chris Servheen. . Due to the speed that bikes travel, Servheen concluded that mountain bikes pose a significant threat to grizzly bears, as well as bike riders. Serhveen was quoted: “High speed and quiet human activity in bear habitat is a grave threat to bear and human safety and certainly can displace bears from trails and along trails. Bikes also degrade the wilderness character of wild areas by mechanized travel at abnormal speeds.”

Wilkinson’s article noted that Matthew Schmor, a graduate student at the University of Calgary, summarized survey data he collected from 41 individuals in the Calgary‐Canmore region who had had interactions with bears while mountain biking. Some of the interactions were aggressive encounters in which a bicyclist(s) was charged or chased by a bear(s).

Schmor found that 76 percent (31 of 41) of mountain bike riders had not contacted officials about their bear encounters.” This is important because some organizations suggest that if mountain biking (and other recreation) poses a threat to wildlife, they can monitor and enforce restrictions. But if most encounters are unreported, then limits are less likely to be imposed.

Dr. Brian Horesji, a wildlife biologist from Canada confirms that bikes can displace bears, and other wildlife with negative consequences. He writes: “The basic science solidly supports the general claim that bikers and bikes are displacing bears, can contribute to their habituation and are consequently adding negative load on human / wildlife conflict. I think it has been conclusively established that most kinds of human activity / presence displace bears (and almost all other species), and if there are bears that are not displaced / become habituated, they die at a disproportionate rate, hence their fitness is reduced (as is that of there mothers and fathers). Amongst the leading agents of displacement are industrialized forms of human activity that depend on machines / motors / mechanization to move people great distances, often, quickly, and with considerable “baggage” (garbage, guns, trailers, ATVs, dogs, and so on).”

Horesji goes on to talk about cumulative impacts. “The demand / need for refuge from humans is greatest when human use is highest, usually on weekends. Previously un-biked niches in the landscape are of disproportionate value during these peak periods. So, what happened?  These refuge habitats were dissected by bike roads, which is destructive enough, but biker use also peaks on weekends, aggravating habitat loss at a time when demand / need for it is greatest, so the negative impact of biker use is not linear in relation to the increased number of bikes, but exponential given the elevated need by wildlife.”

According to the Colorado BHA report, for a given time frame of recreation, not only do mountain bikers adversely impact big game 4 times as much as hikers, they affect 50% to 75% more animals.


Worse, correspondingly, many so-called conservation groups are advocating for “Backcountry Area” designation in place of supporting wilderness designation. The California Wilderness Coalition (CWC), the Montana Wilderness Association (MWA), and the Deschutes Chapter of the Sierra Club are among the many environmental groups that support “backcountry” “conservation area” or other alternative classifications for wilderness-quality lands to appease mountain bikers. For a discussion of this issue of wildlife management designation for Montana’s Gallatin Range see:

For instance, in a letter articulating their support for Backcountry designations, the CWC says: “The proposed BMA prescription intends to conserve roadless lands while allowing for more recreational activities and management flexibility than is permitted in recommended wilderness.”

But such designations often permit many other activities that wilderness designation would preclude. For instance, the CWC supports logging in backcountry areas for so-called forest “restoration.”

See the following link for more in depth discussion of the problem of alternative designations

Many of the conservation groups supporting designations like Backcountry, Wildlife Management Areas, Conservation Areas, and other non-wilderness alternatives suggest that conflicts with wildlife (and other recreationists) can be controlled with monitoring and enforcement of seasonal restrictions. However, it’s critical to note that limitations are only as functional as the political will and the funding to enforce them-which in most cases is zero.  Plus “solutions” like seasonal closures or alternative day designation for different uses, etc. are only attempting to mitigate adverse effects.

The Gunnison National Forest in Colorado has concluded: “No positive benefits to wildlife have been identified from increases in travel management access.”


One of the things I analyzed in my Thrillcraft book was the general “theme” of Thrillcraft advertisements. Those ads glorified speed, conquering nature, and “going where no one has gone before.” Similar themes appear on the covers of mountain biking magazines and in the ads. Nearly all prominent photos show a mountain biker racing downhill and often flying through the air.  “Fast and furious,” says one ad. “Strikingly fast,” says another.

To many thrillcraft advocates, including mountain bikers, the natural world is merely an outdoor gymnasium where they play.

By comparison if you were to review ads for hiking gear, the theme is more sedate, and about being out in and appreciating the natural landscape. In other words, some recreational pursuits are more about bonding and learning to respect the natural world, while others are about self-glorification.

The iconology of these ads also says much about the mountain biking culture. Compare side by side photos of dirt bikers and mountain bikers, and you will be hard pressed to tell the difference. Both wear gaudy shirts with company logos, crash helmets, and other protective gear.

One of the rationales given by mountain bikers to justify the ever-expanding trail systems is that it allows one to get closer to nature or out in nature.

But if one takes the industry advertisement as insight into the mind of the user, communing with nature is not the primary goal. Instead it seems the main goal is tearing up the miles and self-gratification. Roaring along at high speeds on a machine is hardly conducive to communing with nature.

If anything, thrillcraft use exacerbates our society’s alienation from nature, creating a barrier that separates people from experiencing nature on its own terms.


I have not dwelled on the social impact that mountain biking can have on other recreationists because this is ambiguous at best. Mountain bikers are viewed more favorably than say motorized recreationists, though with the growing popularity and speed of electric mountain bikes that distinction may soon be reduced.

Nevertheless, there is evidence that increasing mountain bike trail usage displaces other recreationists as much as it does wildlife. If one is continuously looking over your shoulder for a fast-moving bike barreling down the trail towards you, the peaceful enjoyment of a walk in the woods is compromised.

A 1999 Montana study of the impact of Off-Road use on hikers demonstrates this disparity. Although somewhat dated, the study found that 90% of trail users in the state were hikers and only 2% were Off Road users.  When questioned if the presence of ORVs on trails bothered a person, some 89% of the hikers agreed that the presence of ORVs diminished their enjoyment of the area. Though the study was done before mountain biking became popular, their effects of mountain biking on other recreationalists are likely the similar.

CONCLUSIONS: Given the rarity of lands that could even qualify for Big W or wilderness classification under the 1964 Wilderness Act, as well as the growing body of scientific literature demonstrating that recreation, including mountain biking, can pose significant threats to our wildlife heritage and biodiversity preservation, conservation-oriented groups and individuals must advocate strongly for wilderness designation of our remaining wildlands and restrictions when necessary on the growing impact from recreation of all stripes, but in particular, mountain bikes.


  1. Michael Lewis Avatar

    Thanks for this excellent article, George!

    We’re fighting a local, industry supported mountain bike group here in Santa Cruz, wheedling their way into Parks and Recreation Departments hearts by building trails for them.

  2. Richard Popchak Avatar

    Bravo! Your comprehensive treatise conveys the pertinent research and the urgency. Thank you. I will use this information in my arguments against mountain biking in Wilderness … and in a broader sense … the impacts on wildlands (and wildlife) in general.

  3. Frank Krosnicki Avatar
    Frank Krosnicki

    Thanks for another great article that will, sadly, fall on deaf ears. Many of the advocates for biking expansion into Wilderness are the same people who correctly espouse clean air, conservation, and are against the use of plastic bags. However, don’t we dare try to take away their fun and rights to our wild lands.

  4. Chris Zinda Avatar
    Chris Zinda

    “…groups and individuals must advocate strongly for wilderness designation of our remaining wildlands and restrictions when necessary on the growing impact from recreation of all stripes (PERIOD).”

    The included caveat indicates a begrudging conclusion on impacts of all forms of recreation and still does not address carrying capacities and quotas for all uses.

    Bikes are the topic of the day, treating the symptom rather than the source, meaning controlling all human anarchy on wildlife habitat that importantly includes public lands containing so-called wilderness as last refuge during the apocalypse.

  5. George Creal Avatar

    While I appreciate your concern for preserving wildlife and wild spaces, you article is more speculation and conjecture than fact and reason. Many of the studies you cite are based on inference and extrapolation or from studies that are observational only. Correlation does not mean causation. First, Rogue trails are illegal and existing law should simply be enforced. Trails can be closed and obstacles constructed to prevent use. Second, Electric Mountain bikes are motorized vehicles and motorized vehicles are prohibited already. The solution is simply to enforce existing laws. Third, Mountain bikes have arguably smaller impact than hiking as there is typically no over-night camping or food consumption, preparation or disposal. Third, there are four categories of Mountain Biking: Cross Country, Downhill, Dirt-jumping/obstacles and free-style. Of these four only cross country applies to wildlife areas and woodland trails. Lumping them all together as “thrill culture” is uninformed and misleading. In Georgia recently, a several hundred acre wood land park in Roswell, Georgia was saved by mountain bikers from being bull dozed into an enormous tennis center. Mountain bikers are allies in the fight to preserve natural spaces. Picking on Mountain bikes is unfair and unwarranted. Instead of declaring war on mountain bikers, you should reach out and engage in conversation, understanding and cooperation. I am sure your concerns would be well received by Mountain Biking organizations as opposed to defaulting to an “us” vs. “them” mentally that is so prevalent today.

    1. idaursine Avatar

      A waste of time. Hikers don’t always camp overnight of bring food! That sounds like another subcategory.

      A woodland park is not what this is about. True wilderness should remain undisturbed by all, because there is very little of it left. I thank those mountain bikers who understand this and cooperate in that way.

      1. idaursine Avatar

        I say waste of time because the tired refrain of ‘ngagement, conversation, understanding and cooperation’ is usually an abject failure.

        Because as we can see with wildlife preservation and land preservation, for many, it can never be enough and they will always push for more and more access.

        Roads and trails of all kinds are shown to be detrimental to wildlife.

    2. Hiker Avatar

      George, this article is about Wilderness. I applaud your efforts to preserve ‘natural spaces’ but there is a difference. True Wilderness needs maximum protection, there’s not much left. Creating trails where none belong is what I’ve witnessed from mtn. biking. Keep the new trails out, I agree with you. And keep all bikes out of Wilderness, like the current law states, now and forever.

    3. Todd McMahon Avatar

      George Creal made the most ridiculous statement yet. He Wrote “Mountain bikes have arguably smaller impact than hiking as there is typically no over-night camping…” The point George misses is that mountain bikers can get up the next day and go out riding again making their impact much greater. It’s much greater because they cover much more ground than a hiker. And somehow George seems to believe that mountain bikers don’t eat. George, just face it, Wilderness Areas are less than 3% of the land area in the lower 48 States. If you want cooperation between mountain bikers and hikers they can achieve that on the other 97% of the land that is not Wilderness. Let’s give wildlife some room the live.

    4. Greg Henning Avatar
      Greg Henning

      100% correct. We have a small group of mountain bikers who maintain 15 miles of trails that everyone can enjoy. We host trail running races and organize rides for all skill sets. We have several other mountain bike groups in our area who work very hard taking care of 100 miles of trails. We have heard this argument before with videos of professional down hill racers as typical thrill seekers were used to frighten the general public,

      1. Hiker Avatar

        Thank you for supporting your local trails, but you must admit you do it for yourselves, I do. Meanwhile I have seen plenty of regular mtn. bikers who are clearly thrill seekers, creating jumps and trails where none existed before. Why mtn. bike at all except for the need to go fast? That in itself promotes thrill seeking. Try hiking for once and enjoy ALL aspects of the trail; the sights, smells, sounds, even the feel of the ground under your feet. You are missing out on the joy’s of experiencing nature.

      2. Todd McMahon Avatar

        Let me get this right. You’ve got “100 miles of trails” in your area that you can go mountain biking on, yet you insist that you need to ride in Wilderness Areas. I say let’s let the wildlife have some space and keep mountain bikes out of Wilderness Areas. Mountain bikers have never shown any data that suggests they need more trails.

    5. Jim Fuge Avatar
      Jim Fuge

      Well put George,… I agree. I remember when mt. bikes first started appearing in back country environs. The big scary threat was multi-trailing/ single tracking et al. That argument was obviously not a true and was quietly dropped off the complaint radar.
      This article tries to make its case using a shotgun approach of supposed evils,..none of which jump off the page and grab ya or our proved in any convincing ways as being real or serious threats.

      1. Hiker Avatar

        I see evidence for this article every day. Mtn. bikes cause problems. They don’t belong in Wilderness areas. End of story.

  6. idaursine Avatar

    It’s truly shocking. It can never be enough. It’s too bad that the FS or whatever group is responsible for the caretaking of our public lands can’t continue to disable the illegal bike trails instead of caving in and accepting them!

    I’m sure that any disturbances to elk and calving will be conveniently blamed on wolves and bears.

  7. Monica Craver Avatar

    Mountain biking has always been an off-road dirtbiking sport, akin to motorized off-roading no matter how the industry and tourism hacks have painted it. Now that the motorized e-bikes are elbowing for room on the trails, it will only get worse…

    And excellent article that paints a serious growing problem, everywhere mountain bikers choose to ride and dig endless trails…

  8. Michael Soule Avatar
    Michael Soule

    Let’s be honest. Mountain bikers in wilderness are thrill-seekers. I don’t believe that most of them truly value wild places for their own sake. The best way to appreciate the wild is to sit down and be quiet; only then will one discover the real nature and values of the wild. The radius of wildlife disturbance by rapid propulsion in the wild is about half a mile. There is nothing wrong with thrill-seeking, but please do it where it does no harm.

    1. Jim Fuge Avatar
      Jim Fuge

      I’ve been riding bikes in forests and backcountry since the late 70’s,…even if thrills were the singular motivation so what?
      Which by the way it isn’t. I also climb mountains and run rivers which have thrill-seeking elements,…they both carry considerable potential for harm, harm to who and what …really measurably how much and what kind and how serious. Yours is a complaint looking for a problem.

      1. Hiker Avatar

        Jim, the harm Michael was referring to was harm to sensitive Wilderness areas. Bikes DO cause harm. Collisions with animals and people, shortcutting trails, building new trails, widening existing trails. All of which I have witnessed in my area. They do not belong in Wilderness areas.

  9. Rob Shaul Avatar

    I am the Founder of Mountain Pursuit, a Western States hunting advocacy nonprofit headquartered in Jackson, Wy. We agree completely, esp. in rapidly growing areas like Jackson and Bozeman. We are currently pursuing litigation vs. the USFS to stop the expansion of MTB in the Palisades and Shoal Creek WSAs. More on our efforts here:

    1. idaursine Avatar

      Thank you!

  10. Martin Phillips Avatar
    Martin Phillips

    I’ve been mountain biking for 30 years and have tens of thousands of trail miles under my wheels. I’ve rarely met “most” mountain bikers “most” of us apparently are. Clearly mountain bikers are not your intended audience and finding reasonable compromise is not what you are interested in. Just another shrill, uninformed voice shouting from the rooftops that they are right. Congrats! You’ve advanced your position exactly zero inches.

    1. Hiker Avatar

      There is no “reasonable compromise” with protecting Wilderness. Bikes are just too disruptive. I see it all the time in the Forest Service area behind my home. They constantly make shortcuts and widen the trail. They make jumps where no trail exists. They try to make new trails, which I close with rocks. I’ve never met them either, but clearly they exist. I see their bike tracks and that’s evidence enough.

    2. Jim Fuge Avatar
      Jim Fuge

      Touche’ Martin and thanx!

      1. Hiker Avatar

        Jim, Martin is wrong. Mtn. bikers that cause problems do exist. I’ve seen it first hand. Maybe you mtn. bikers are going too fast to notice.

    3. Don Christensen Avatar
      Don Christensen

      Well said!

      1. Hiker Avatar

        Don, who is “Well said!”? Let’s be clear.

  11. Bruce Bowen Avatar
    Bruce Bowen

    Ain’t America Great! The conflicts only escalate because the groups that embrace technology must have their way and manufacture excuses for their abuses. They gotta have their rights even if they mess stuff up. Their sport makes money so they see themselves as being blessed by the gods of capitalism. Nature is still seen as something to be distrusted and something to be tamed down and subdued. They totally ignore cumulative impacts. Other people and animals are viewed with fear and contempt for disrupting their competitive endeavors in which they act out the metaphors of western expansion and hierarchical society. Nothing is sacred. That is why America will ultimately fail.

    I noticed an article by Michael Paul at which includes the following as threats against mtn bikers.

    Mountain lions, bears, antelope and deer, moose, squatters and drug traffickers, hiker/biker animosity and equestrian /biker animosity. (Anybody been attacked by a rogue antelope lately?) He notes that he rides with a small group of bikers where somebody in the group carries a .45 cal pistol. He ends his article with a photo of a backpack with a hand gun on it and a bike in the background. Makes me feel like if I dare to walk on a trail used by bikers I’d better have a bullet proof vest on.

    Holy crap-if it’s that dangerous in the backcountry -just leave it to the critters.

  12. MAD Avatar

    There’s over 27 million acres of federal land in Montana. There’s about 3.4 million acres of designated wilderness areas. So even if there’s about another 5-6 million acres of federal land that’s not open MTB, are bikers saying that 10 million acres of land that’s open is NOT ENOUGH?

    I am convinced that the MTB community will never be satisfied until every acre of public land is opened to them.

  13. Kathleen Fitzsimmons Avatar

    Encouraging mountain biking or cycling, in general, is needed. This effort or more specifically the impact mountain biking has on our National Forests and BLM land is insignificant compared to the ever-growing dependency we have on the automobile and petrol powered civilization we live in. Building roads, expanding highways, putting more traffic and therefore pollution into the atmosphere is happening at a much faster and much more damaging rate then mountain bike travel. The % of people even capable of mountain bike travel is tiny compared to the population in mass transit. The % of people even capable of bike camping is even less. Organizations that exist that develop trail travel also are very educated and funded to maintain any new trails. Unlike road travel, their support is not apart of our tax system, which is imposed upon us. Trying to say mountain bike travel is endangering our wildlife is unequivocably unfair. Road and highways take up much grassland, and land in general, altering migration routes, causing road kill, and adding significantly to air pollution. The easiest way to reduce trail travel would be to eliminate trail parking lots first. Thus making trail access available only by bike, foot, horse or the like. If wildlife habitat is a primary concern, then we need to stop building roads and overpopulating this plant with people.

    1. MAD Avatar

      The issue is not whether MTB is bad per se – the core issue is whether there are certain activities, MTB being one of them, that should be excluded from certain, specific areas – not all areas. I have NEVER heard an environmentalist or conservationist say that MTB is bad. In fact, most people who consider themselves environmentalists or conservationists ride bicycles or MTB.

      When looking quantitatively if MTB is more of a threat to wilderness than urban sprawl, overpopulation and resource extraction, then the answer is probably no. But just because something is less of a detriment should it then be promoted? The other issues are socio-political and encompass players who influence local, state and federal politicians and will probably never be controlled. So are we then to just allow the floodgates to open? You know what, open every area of public land to maximum exploitation of commercial and recreational uses. Let no stone go unturned in the pursuit of the almighty dollar and the thrill-seeking citizen. Leave nothing in a better condition for our children and grandchildren.
      A few years ago I heard a talk that included several Native Americans from various tribes here in Montana. Tony Incashola from the Salish tribe put it best: we are only on this earth for 80-100 years and it seems long, but in reality it is a short period of time, so we don’t have time to really own anything. because to own something is to take with you or to have with you – and you can’t take land. So what see here is not necessarily yours to own, but yours to protect. Yours to make sure that what you enjoy, what you utilize and benefit from is the same thing that your children and grandchildren will benefit from – and they will experience the same thing that was given to you by your parents & grandparents. In your lifetime you have to do the best you can to preserve, protect and perpetuate the land.”

  14. idaursine Avatar

    I ride an ordinary bicycle occasionally, but not a mountain bike and would not.

    Transforming our automobile and highway system and modern society is very unlikely to change; the damage is done there. But certainly tearing up new areas of wilderness for mountain biking is more of the same?

    Trying to keep the last remaining 3% I think is the figure of wilderness is the point. If the mountain bikers gripe that hikers are allowed in areas where they are not, I and many other hikers are willing to give it up for the sake of wilderness and wildlife. Are they?

    1. Kathleen Fitzsimmons Avatar

      Mnt Bikes don’t need to expand into the wilderness. The wilderness is super rugged and not suited for mnt bikes anyway. I can think of a couple of trials that might be considered an exception as they would only nip into the wilderness and are not as rugged. Let’s face it, with increased population there is just an increased demand for space, everywhere. Thinking that by restraining mnt bikes is going to somehow change this need or reduce the impact upon the public lands is unfounded thinking. Saying that the damage is already done regarding the mass traffic issue that we have is only adding to the problem by not addressing it. Bikes are nothing compared to the traffic issue. Wildlife needs more than an allotted space. Our roads disturb access to water/rivers, migration routes, natural grazing lands, breeding grounds and more. Thinking that by restricting trail use is the answer to save our natural wildlife habitat is missing the point. I am totally an advocate of planned trail expansion, riparian work, maintenance, and traffic distribution. The point I’m making is that our concern about saving the wildlife habitat is a much much bigger conversation. The best trail users can do is be smart about trail use and management.

      1. Hiker Avatar

        Did you not read the article? Many mtn. biking groups are actively trying to gain access to Wilderness for mtn. bikes. This is happening right now. Many here are very concerned about this because we want to protect the little Wild that’s left. I am not against responsible mtn. biking, but I am against bikes in any Wilderness areas. Bikes have plenty of places to go, keep them out of our Wilderness.

        1. Kathleen Fitzsimmons Avatar

          I can agree with keeping bikes out of the wilderness. However, there might be a few exceptions where wilderness trails are or have become within close proximity to easy access. It’s my opinion if it makes sense to include a short piece of wilderness trail to better distribute trail use or for a similar reason then it should be considered. As far as expanding into the wilderness, not a good idea. I have also seen super nice mountain bike trails get turned into wilderness. Not sure that’s really necessary either. This particular trail I’m thinking of has been more or less abandoned from that time. The Forest Service is supposed to be maintaining it but that’s not happening, not even for hikers and especially impassible for horses. I’m still of the opinion that limiting trailhead access by limiting or offering no parking at the trailhead is a better way to minimize use impact.

          1. Hiker Avatar

            No biking in Wilderness ever, no exceptions. Once that door gets opened who knows how far it will go.

            1. Kathleen Fitzsimmons Avatar

              There is ever-growing pressure for more and more recreational use of our forest, BLM, and wilderness. Making minor adjustments to satisfy the best use case scenarios is not ridiculous thinking. Keeping an uncompromising, unaltered outlook on anything is opening the door for problems.

              1. Hiker Avatar

                No, changing the rules to suit users who cause significant damage is opening the door for problems. Do you mtn. bike? Do you live near where it occurs? In my neck of the woods there is extensive mtn. biking and also wilderness where it does not take place. The difference is startling. Mtn. biking leads to wider trails, short-cuts and more wildlife disturbance.
                Just because there is pressure to change doesn’t mean we should. In fact often it means we shouldn’t.
                Also, we are not talking about ‘minor’ adjustments.

  15. idaursine Avatar

    ^^or ‘trying to keep the last remaining 3% of wilderness protected’, that should read.

    Fossil fuel pollution is not the only form of damage. Many of us drive low or no emission automobiles too.

    Mountain bike travel endangering wildlife (and the riders themselves from dangerous encounters) has been shown in studies. We should not have wildlife moving from their habitat or even being ‘euthanized’ because of the presumed superiority of people on the land. Enough is enough.

  16. idaursine Avatar

    How apropos:

    Why court disaster? And why push wildlife out of their last remaining refuges so that people can ride a bike, which is trivial IMO.

  17. idaursine Avatar

    If anyone needs any proof that continued encroachment into formerly roadless areas damages wildlife, look no further than the Selkirk mountain caribou and snowmobile access and what compromise can do:

    And today, they are functionally extinct.

  18. idaursine Avatar

    Here’s a pretty good article from a hunting magazine. While wolves still catch some of the blame (unfairly, I feel), the article does give consideration to the effects of recreational activities on the herd:

    “Perhaps one of the most debated subjects along the recovery efforts for the Selkirk caribou herds lies in the recreational activities of the public, primarily in snowmobile use. Snowmobilers are often times looking for the deepest power and steepest terrain they can find. Coincidently, this is also the type of areas that are typically used by mountain caribou for wintering grounds. The increase of wintertime recreation will lead to increased stress on the animals at a time where every ounce of energy is needed. Additionally, a surprising number of predators were found to also use the pack tracks of the snowmobiles to access the high country.”

    1. Kathleen Fitzsimmons Avatar

      Snowmobiles and other motor vehicles in the wilderness should not be allowed. I don’t think bikes should be either; however, bikes are a far cry from the damage of a fully motorized vehicle in the wilderness.

      1. idaursine Avatar

        It’s a good parallel, though, I think, and motorized or mechanical, it can either cause avoidance in habitat, or an outright danger. And the animal never comes out the winner, regardless of the intent of the rider, when public safety is paramount.

  19. idaursine Avatar

    ^^avoidance behavior and stress, I should say.

    Also, when talking about ‘predators’ using these trails and new access roads for track prey, we can include poaching by humans as well.

    Guns in our National Parks, and continual new trails is a recipe for disaster for wildlife, I think.

  20. Hans Avatar

    Before I say anything I want to say one thing.
    There are wild places on the planet that should be off limits to humans and in the places that are humans go we need to make plenty of space for other creatures. That being said, alienating groups of people who enjoy being outdoors is alienating a constituency that otherwise could be turned into conservationists / environmentalists. Look at the response to Trump’s de-monument-ing Bear’s Ears and Grand Staircase. Led by recreationalists teaming with environmentalists. This is a potential coalition that can team up to save a LOT of the planet. There is plenty of opportunity to turn MTBers into conservationists, but not with the rhetoric in this article. The number of incorrect facts and assumptions in this article is astonishing as are the amount of people who are chiming in that it is gospel. You’d think with climate change and rampant development that there would be larger items that this group would want to tackle. Maybe start with zoning code that aggressively bans density and encourages development in much needed valley floor habitat? What about oil and gas development in migration corridors? What about conservation easements that still allow people to build upwards of 10,000 SF? What about cattle grazing?
    If you want to protect wildlife, start with the list above and look for ways to reach across the aisle to those who value the same things you do. –

  21. Rico Sauvin Avatar
    Rico Sauvin

    To clear some things up. These e-bikes you speak of as the devil typically weight about 45 to 50 lbs. They are not throttle assist, so they are not realistically mountain bikes, you still have to pedal them. Hence the “pedal assist”, if you do not pedal them they simply go nowhere. The batteries typically last about 2-5 hours. Not really a great place to get stuck out in BFE with a 50 pound bike without a way to charge a battery. Point is, Ebikes are not a threat to wilderness or any other backcountry trail area because of all the inherent problems with a 50 pound piece of bicycle breaking down 15 miles out from a trailhead. Leading one to pedal such 50 pound bicycle both up and down hills, which basically sounds like a pretty terrible weekend of getting away from it all. Bicycles pose very little harm to trails themselves because, well the trails are already there. It’s not that fun to take a mountain bike off the trail that was built for such travel. If you would like to discuss erosion of soil than speak to the hikers and equestrians that would rather go around downfall on the trail than properly clear it using a handsaw. Rogue trails you say, last time I cut a switchback on a mountain bike was never on a trail. If I can’t clear it, I simply get off my bike and walk for a bit. Pretty sure there was just recently a trail here that the USFS had to spend a week on repairing rogue trails cut by hikers and horses to avoid using switchbacks causing a rock slide.

    Just because you were not taught how to share in kindergarten doesn’t mean you can’t grow up. Some of my favorite rides include going out and getting lost for a day in the backcountry and stopping to take in the sights and vistas. I would love to do it hiking, unfortunately I work 65 hour a week and can cover the same ground on my bike in a day as I could hiking for 3 days. This whole argument is so politically based it’s ridiculous. A giant competition between those with money and those with little. A group of thrill seeking youngsters with no class vs. a group of hardened purists who want the backcountry to themselves. I think the new skis and bindings we backcountry ski with are another example of evolution, but no-one seems to care that these are just as mechanically advances as a bicycle chain.

  22. Vinski Avatar

    Living on the edge of the Palisades wilderness it’s hard to accuse mountain bikers of being a major concern when the trails here are really not human powered friendly. I’ve ridden many of the trails (certainly not all) but find that my impact vs the multitude of dirt bikes is minimal comparatively. You have hundreds of folks hiking on the weekends with only one or two cyclists. You have dirt bikes ripping up existing trails plus helicopters and snowmobiles all winter. I think you will find a more cooperative approach in promoting well built trails in approved locations first before talk of banning in study areas. Mountain biking isn’t going anywhere so it’s got to be a trade off. I’ve never seen a trail “V’d” out from mountain bikes and we are silent so get after the dirt bikers if you want to make a difference. The core cyclist groups are more concerned about erosion, wildlife impact than done may think and I can tell you the dirt bikers care not. It’s all about horsepower to those guys.

    1. Hiker Avatar

      Vinski, obviously dirt-bikes don’t belong in Wilderness and so not in study areas either. The issue is whether or not mtn. bikes belong, they do NOT. You would have us compromise. There should be NO compromise for Wilderness. There is not much left, it deserves to be preserved as close to natural conditions as possible. There is millions of acres where mtn. biking is allowed. How much is enough?

      1. bill kinzel Avatar
        bill kinzel


        lots of good commentary here. i am an outdoorsperson. i hike, snowshoe, ski and am an avid mountain biker and trail volunteer.

        i’ve recreated outdoors around the world on bikes. yes there are bad actors in the biking world. but times are changing. i’m a cpa and a professional. i am not out denuding the environment

        in fact i agree with your author here on many topics, like for example the fact that livestock trash the environment. I’ve ridden with livestock in the salmon Idaho area and its painful to see the environmental damage they do. in fact i limit my meat consumption accordingly.

        i digress…

        i mountain bike in areas in Washington that are under consideration for wilderness designation. each year i make the pilgrimage into the forest to ride legally and note that bikers are the only ones maintaining (cutting trees and brush) trails that otherwise are essentially not getting used.

        without bikers these trails simply will go back to nature. which if that’s your goal then fine i respect that opinion but i know i do not want to live in a world where our existence is purely cities and forests where humans are confined to the city with no access to the woods.

        agreed that motos, jeeps and quads can lay waste to the forest but my little 25 lb bike with my 170 lb frame spinning around at an average of 7mph is not causing any more damage than a 1,000 lb horse or a 200lb hiker with 50 lbs of gear.

        hope to continue to see everyone enjoy the trails harmoniously!

        if you have not already i do encourage folks to get out and say hello to each other. bikers are not scary people. we are also hikers, humans, volunteers and good citizens.

  23. Grant Normand Avatar
    Grant Normand

    I found the article interesting and I am glad people are thinking about this from another view point.

    I am a mountain biker, I have been for quite some time. One thing I can say for most mountain bikers is that we cherish the places in which we ride. A large part of the beauty of mountain biking is the ability to be in nature, to be in places largely left to their own devices.

    The irony in your story, at least in regards to the places I frequent, is that the most destructive trails that I see are actually used for the fire department (hence the term fire roads). Most smaller hiking, equestrian, and biking trails taper of from these roads.
    I can certainly see how the presence of any frequent traffic, biking or not can disrupt wildlife. However, I fail to see the epidemic you speak of when the trails we frequent are 2-3 ft wide and were typically a result of wildlife traffic to begin with.
    Generally speaking, the truth lies somewhere between. I certainly agree that trail building should be monitored and controlled more closely and perhaps mountain bikers should avoid unmarked trails.

    That being said, I don’t think it is fair or logical to try to an expel an entire community of people. Especially considering that having hiking trails is okay? I think there is an achievable middle ground here.

    Of course you have written a book on this subject so this is my two sen

  24. Dave Thompson Avatar
    Dave Thompson

    The best thing we can do to help wildlife while preserving recreation is to restrict parking at and near access points to wildlife corridors. This will lower the overall number of trail users and reduce the number of motor vehicle trips, which take a much heavier toll on wildlife than any form of human powered travel.

    1. Hiker Avatar

      Dave, maybe the goal should be to preserve ecosystems and NOT “preserve recreation”. Even so, have you ever been to a crowded trailhead on a busy weekend? If so you’d realize that illegal parking takes place on a massive scale. Also, those who still can’t park endlessly cruise around looking. Not exactly the way to “reduce the number of motor vehicle trips”. I suggest you reread the article and discuss how mountain biking affects the area. When in doubt maybe we should err on the side of protection, like our ancestors did, occasionally. Our descendants will thank us.

  25. Simon Alford Avatar
    Simon Alford

    Thanks for opening my eyes a bit to the dangers of mountain biking. I recently started mountain biking and love it.

    Wilderness areas should not have mountain bikers. That being said, there should be some room for agreement. There can be a tradeoff between recreation and preservation. We already make such tradeoffs when allowing hikers in wilderness areas. Bikers may cause more harm than hikers, but the damage is on the same order of magnitude. I would say, a group of 5-6 rowdy hikers does that same amount of damage as a pair of mountain bikers.

    Everyone seeking to enjoy nature should be accommodated, while ensuring we don’t encroach on the amount of wilderness preservation we desire. If there are 10 bikers and 100 hikers, then don’t give the bikers as many trails. But you can’t ban them from all trails.

    I’m very sensitive to the concern about wildlife disturbance from hiking and biking. I’m not sure what the right answer there is. But I still think that if hikers get wilderness to explore, then so should mountain bikers.

    I agree we don’t need endless proliferation of trails criss-crossing the wilderness. But a few here and there are worth it. There is room for compromise.

    The best thing to do is set off efforts to dramatically expand the amount of undeveloped land. The number of nature-seekers is only going to increase over the years, and as they increase, they’ll encroach more and more upon wildlife. Get some nice dense cities and buy back rural land to convert back into its natural state.


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