Air quality concerns related to snowmobile usage in national parks

Air Resources Division

National Park Service (NPS) regulations (36 CFR Part 7 and 36 CFR Part 13) allow snowmobile use in more than 40 of the 378 units of the National Park System (see Appendix A, Table 1). The amount of use, and associated impact, varies greatly among units. For example, in the winter of 1998-1999, only about 10 snowmobile groups entered Mount Rainier National Park (NP). On the other end of the spectrum, during the same time period, more than 76,000 tourists visited Yellowstone NP on roughly 63,000 snowmobiles, with nearly 54,000 visitors travelling via a single corridor from the West Yellowstone entrance in Montana. There are various environmental and health impacts associated with the use of snowmobiles in national parks, including air quality impacts from exhaust emissions. The Bluewater Network, a coalition of environmental organizations, has petitioned the NPS to ban snowmobile use in units of the National Park System. The NPS is currently considering the petition. The intent of this paper is to present information regarding the potential air quality impacts associated with snowmobile use in national parks. This information, in conjunction with other available information, will enable the NPS to make informed decisions regarding the use of snowmobiles in units of the National Park System. This report summarizes available information and reports related to the air quality impacts of snowmobiles. It is necessarily limited by the scope, methods, and content of the studies cited. It provides a general overview of highly complex technical data. Although it relies heavily on information obtained from studies conducted at Yellowstone NP, it is not a complete compendium of the extensive studies that have been conducted there and in other areas. The comparisons made using Yellowstone data could be viewed as a high use scenario and apply only to Yellowstone. However, the results from Yellowstone demonstrate the impacts on air quality that may result from heavy snowmobile usage in an area. As the popularity of the sport grows, so will the potential for air quality impacts on park resources, as will the need for park managers to carefully consider these impacts in their decisions.