The Legal Status of Snowmobiles and their Effects on Bison in Yellowstone National Park

Taken From: Adverse Effects of Trail Grooming and Snowmobile Use on Winter Use Management in the Greater Yellowstone Area with a Special Emphasis on Yellowstone National Park, by D.J. Schubert, Wildlife Biologist, Meyer and Glitzenstein, on behalf of the Fund for Animals, Inc.; Wildlands CPR; Predator Project, BLF, Bison Advocacy Project, and Defenders of Wildlife.

Although this report focuses on the impacts of motorized winter use on bison, not just big animals are affected by snowmachine use (RIPorter vol. I, no. 4). Activists can and should incorporate many of the impacts described here, since they are pertinent to contexts extending well beyond the boundaries of Yellowstone National Park or the American bison.

Snowmobiles and snow coaches impact many types of "subnivean" animal lifethat is, creatures which live below the snow. In one study, for example, researchers reported a marked increase in mammal mortality beneath compacted snow. They concluded that, "Mortality of subnivean mammals in the area packed by snowmobiles was probably due to a combination of factors that increased winter stress to the point where survival was impossible. Mechanical compaction of snowfields will:

    * destroy subnivean air spaces
    * reduce snow depth
    * increase density, thermal conductivity, thermal diffusivity and shear strength of snow.

These effects would in turn be inhibitory to mammal movement beneath the snow and at the same time subject subnivean organisms to greater temperature stress. There is also the possibility that air beneath packed snow may become toxic because of abnormal carbon dioxide accumulation" (Jarvinen and Schmid 1971).

Plants are also damaged by snowmobiles. Neumann and Merriam (1972) reported that 345 of 440 saplings on a snowmobile trail received severe (118) to minor (227) damage as the result of a single passage by one snowmobile. The authors predicted that those saplings which suffered severe damage would probably die. In another study, seventy percent of the trees in the area were damaged by snowmobiles.

Snowmobile use in Yellowstone National Park began in the early 1960s. By 1968, when numbers had climbed to 5,000 winter visitors, the business community surrounding the park recognized the economic boon and demanded recognized winter access, which was granted. Today, nearly all the roads in the park are groomed for winter off-road vehicle (ORV) use. Last winter, 1995-1996, the number of snowmachines using the Park was recorded at 74,859.

Preliminary results of 1995 and 1996 studies of air quality at Yellowstone indicate that carbon monoxide (CO) levels in the Park exceeded federal Clean Air Act and state ambient air quality standards at times. Results from both years demonstrate a positive correlation between snowmobile density and high CO levels.

A 54.21 horsepower snowmobile (the industry average) running at 75 percent capacity spews 360 pounds of pollution in five hours, about the time for a round-trip from West Yellowstone to Old Faithful and back (McMillion, 1994). For comparison, according to EPA statistics, a modern 150-horsepower automobile engine emits about one pound of the same emissions. Yellowstone endured 26 million pounds of pollution in the 1995-96 season. It seems clear that this amount of pollution results in detrimental impacts to Park flora, wildlife, and users. The Park Service, however, has largely skirted the issue. For example, after complaints from park employees at the West Yellowstone entrance of headaches, nausea, and throat and eye irritation, the park's response was to renovate the tollbooths "to permit clean oxygen to be piped into the toll booths."

Legal Basis for Snowmobile Use

Executive Order (EO) 11644, issued by President Nixon in 1972, was intended to provide a "unified Federal policy" for the use of off-road recreational vehicles on public lands. (Executive Order 11644, 37 Fed. Reg. 2877 (1972) reprinted in 42 U.S.C. § 4321). Its purpose was to "establish policies and provide for procedures that will ensure that the use of ORVs on public lands will be controlled and directed so as to protect the resources of those lands ... and to minimize conflicts among the various uses of those lands." (Id. at §1). As defined in the EO, an ORV means "any motorized vehicle designed for or capable of cross-country travel on or immediately over land, water, sand, snow, ice, marsh, swampland, or other natural terrain..." (Id. at § 2(3)) [emphasis added].

Those areas where ORV use can be permitted should be based on, among other things, "the protection of the resources of the public lands," (Id. at § 3(a)), and shall "be located to minimize harassment of wildlife or significant disruption of wildlife habitats." (Id. at § 3(a)(2)). Within National Parks, such trails shall only be designated "if the respective agency head determines that ORV use in such locations will not adversely affect their natural, aesthetic, or scenic values." (Id. at § (4)).

In Yellowstone National Park, the snowmobile trails were designated to be nearly all of the unplowed roadways. In 1977, an amendment by President Carter, EO 11989, authorized agencies to close areas to ORVs which may be "causing considerable adverse effects on the soil, vegetation, wildlife, wildlife habitat ...until ... such adverse effects have been eliminated and ... measures have been implemented to prevent future recurrence." (Executive Order 11989, 42 Fed. Reg. 26959 (1977) reprinted in 42 U.S.C. § 4321)

In an abrupt and complete reversal of its previous reliance on EO 11644 in designating snowmobile routes, the Park Service reacted by declaring that the restrictions of EO 11644 do not apply to the vast majority of snowmobile use in National Parks. The Park Service simply re-defined most snowmobile use as not entailing ORV use. Specifically, the revised regulation states that: "ORV use is not regarded as an appropriate use in the National Park System. Therefore snowmobiles will generally be permitted to operate on those established roads and on frozen water ways where other motor powered vehicles are allowed at other times. In those very limited places where off-road use of snowmobiles is permitted through Special Regulation, the provisions of Executive Order 11644 and 11989 will be enforced."

Clearly, this new interpretation was designed to avoid compliance with the monitoring and mandatory closure provisions of EO 11644, as amended, by arbitrarily determining that snowmobiles are not ORVs when used on established roadways covered with snow. This is an inaccurate interpretation of the definition of an ORV in the EO (above, in bold) which is based on vehicle design, not type of path traveled.

In addition, park regulations only allow snowmobile use on "unplowed roadways." Not a single regulation authorizes the grooming of trails for snowmobile use.

Effects on Bison

Since the early 1980s, Yellowstone bison that wandered outside the Park have been killed in a politically-charged effort to maintain the Montana cattle industry's brucellosis-free status. This year has proven exceptionally lethal to Yellowstone bisonmore than 1000 have already been killed.

Dr. Mary Meagher, the leading authority on Yellowstone bison, has concluded that "the existence of snow-packed roads... was the largest factor in contributing to population increase, major distributional changes, and ultimately habitat impacts" (Meagher 1993). Groomed trails provide bison with energy-efficient travel corridors resulting in energy savings within traditional foraging areas while promoting range expansion, major shifts among previously semi-isolated subpopulations, reduction of winterkill, and enhancement of calf survival.

The Park Service used to claim that people on snowmachines chasing animals made up for the energy savings, but they have given up that tack: bison don't run. Even bison who are initially skittish around snowmobiles quickly become habituated to the machines (Meagher 1993, Aune 1981), thereby negating energy loss associated with avoiding snowmobiles. For other ungulates, such evasive maneuvers in response to snowmobiles may occur, though habituation has also been observed in mule deer and elk in Yellowstone (Aune 1981).

According to Meagher, Yellowstone's bison population may be nearly double the size that would naturally exist if groomed trails were not present. The functional winter range is quickly declining, but "the park is not experiencing overgrazing in the range management sense...mechanical impact is occurring from increased numbers of buffalo wallows, trails, tree-rubbing, and so forth, especially in Hayden Valley" (Meagher et al., In Press).

With harsh winter conditions this year, Meagher has concluded that the snow density coupled with the declining winter range in the park "dictates that at best there will likely be considerable boundary area removal [a euphemism for killing all the bison outside the park boundaries]. This will be additive with a likely high mortality within the park, such has not occurred since 1981-82 when the bison also really began to use the winter road system. A population crash appears likely, and the system itself that supports bison may be collapsing." Yellowstone National Park supposedly is committed to maintaining "a truly wild, free-ranging [bison] population subject only to the influences of natural regulatory processes" (1983 Management Plan). And yet, instead of eliminating the groomed trails, the park has agreed to participate in an Interim Bison Management Plan which calls for the capture and slaughter of nearly all bison who approach or cross the northern and western borders of the park. Such activities are a far cry from natural regulation.

Clearly the situation for bison would be much ameliorated by closing the park to snowmobiles or at least ceasing to groom trails. While such a prohibition may not stop all bison from exiting the park, this is not the goal of most bison conservationists anyway. The expected increase in winter kill, decrease in productivity, and decrease in calf survival would result in a natural decline in the size of the bison population. This would reduce Montana stockgrowers' perception that bison are a threat to their way of life.

Conclusion

Considering the grievous impacts of snowmobiles on bison, other creatures and the environment of Yellowstone, the Park Service must either "mitigate the impacts" or "eliminate the activity" (Policies, Page 8:1). To date the park has done neither. On the other hand, when unnatural concentrations of native species are the result of human activities, the Park Service is authorized to control the concentrations "if the activities causing the concentrations cannot be controlled." (Id.) But in this case, the activitiestrail grooming and snowmobile useclearly can be controlled, and the Park Service should take immediate steps to prohibit these activities.

Yellowstone National Park should immediately prohibit snowmobile use until such a time as the above violations of law and policy continue. And, whether or not snowmobiles remain permitted, all grooming and other maintenance activities that accomodate snowmobile use should cease.

The Park Service is exploring closing Yellowstone to motorized recreation this winter. In a February 7 letter to Montana Governor Marc Racicot, the Park Service indicated that their options to solve the bison problem "may require closing portions of groomed roads leading from Yellowstone National Park to West Yellowstone and the area between Norris and Mammoth." Other alternatives "involve closing groomed roads to recreational use."

Unfortunately, the Park Service is also considering building barricades to halt bison, again making their commitment to natural regulation questionable.

James Barnes is a founder of the Bison Advocacy Project in Missoula, MT.

Bibliography

Aune, K.E. 1981. Impacts of Winter Recreationists on Wildlife in a Portion of Yellowstone National Park, Wyoming. M.S. Thesis, MT State Univ., Bozeman. 111 pp.

Bennett, L.E. 1995. A Review of Potential Effects of Winter Recreation on Wildlife in Grand Teton and Yellowstone National Parks: A Bibliographic Data Base. Final Report. U.S. Department of the Interior National Park Service, University of Wyoming Cooperative Fish and Wildlife Research Unit.

Daboll, D. 1995. Environmental Impact Assessment Snowmobiling Activity at Yellowstone National Park; With an Evaluation of Multi-Criteria Decision Making Methods. Master's Report MSCE with Program Concentration in Environmental Engineering.

Green, G.I., and D.J. Mattson. 1988. Dynamics of ungulate carcass availability and use by bears on the northern winter range: 1987 Progress Report. Pages 32-50 in Yellowstone Grizzly Bear Investigations: Annual Report of the Interagency Study Team 1987. U.S.D.I. Natl. Park Service.

Greer, T. 1979. Environmental Impact on Snowmobiles: A Review of the Literature, Masters Project. University of Oregon. 60 pp.

Jarvinen, J.A., and W.D. Schmid. 1971. Snowmobile use and winter mortality of small mammals. In Chubb, M. (ed.) Proceedings of the Snowmobile and Off the Road Vehicle Research Symposium. College of Agriculture and Natural Resources, Department of Park and Recreation Resources, Recreation Resources and Planning Unit, Tech. Rep. 8, Michigan State University, East Lansing, MI. 196 pp.

Mattson, D.J., and J. Henry. 1987. Spring grizzly bear use of ungulate carcasses in the Firehole River drainage: Second Year Progress Report. Pages 63-72 in Yellowstone Grizzly Bear Investigations: Annual Report of the Interagency Study Team 1986. U.S.D.I. Natl. Park Service.

McMillion, S. 1994, "Industry Acknowledges Snowmobile pollution," Bozeman Chronicle, Bozeman, MT, January 9, 1994.

Meagher, M. 1993, Winter Recreation-Induced Changes in Bison Numbers and Distribution in Yellowstone National Park. Unpublished Report. Yellowstone National Park files. 48 pp.

Meagher et al., In Press; see also Meagher, Unpublished Research Data, Bison Distribution Flight Report. May 17, 1995.

Neumann, P.W., and H. G. Merriam. 1972. Ecological effects of snowmobiles. The Canadian Field Naturalist. 86:207-212.

USDI 1983 YNP Natural Resource Management Plan and EA.

USDI 1988 YNP Management Policies.

USDI 1990 YNP Winter Use Plan and Environmental Assessment.

USDI 1995 YNP Natural Resource Management Plan.

USDA/USDI 1995 Interagency Bison Management Plan.