Draft Winter Use Plan, Crater Lake National Park, Oregon, 1994
Chapter 5. Environmental Assessment
The Winter Use Plan
There is no evidence indicating that existing winter recreation activities have an impact on water resources. It is unlikely that pollutants build up in concentrations large enough to cause a measurable impact on surface water quality. Use of snowmobiles and other mechanized snow machines is prohibited near the caldera rim and confined to the north entrance road. As a result, oil or other chemicals that may leak from the snow machines do not enter Crater Lake. Additionally, there are no surface water bodies in proximity to the north entrance road that would be contaminated by exhaust emissions or chemicals leaked from snow machines.
To protect water resources from backcountry skiing and camping activities, regulations require that all campsites be located at least 100 feet from any surface water body. Because winter use in the park will remain much as it is under existing conditions, it is unlikely that impacts on surface water resources would occur.
Crater Lake National Park is not heavily used by wildlife during the winter months, because many of the larger animals, such as deer and elk, migrate to lower elevations to escape deep snow conditions. Other animals hibernate during the winter season. The species that do live at higher elevations during the winter are minimally affected by existing winter activities. There is no evidence indicating that existing winter use activities in Crater Lake National Park adversely affect wildlife. Therefore, because use levels would not increase and areas of activity would not change significantly, no impacts on wildlife species are expected to occur.
Snowmobile and motor vehicle exhaust would continue and potentially increase proportional to increased snowmobile use and the number of motor vehicles entering the park. However, neither snowmobile nor vehicle traffic occurs in volumes great enough to cause notable impacts on air quality. It is unlikely that emissions would noticeably increase as a result of plan implementation. Air quality would remain within Class I area standards.
Soils and Vegetation
Implementation of the winter use plan would not cause impacts on soils or vegetation within the park. Soils are covered by several feet of snow during the winter season, and the winter use plan does not propose to develop any structures or facilities to support winter activities.
Snowmobiles are required to stay on roadway corridors used during the summer season; therefore, impacts on vegetation from snowmobile use are not expected to occur. In addition, backcountry fires are prohibited during the winter season to protect standing vegetation.
Threatened and Endangered Species
Implementation of the winter use plan would not have an impact on threatened or endangered species inhabiting Crater Lake National Park during the winter. A pair of peregrine falcons are known to nest west of Rim Village during the spring and summer months, and it is assumed that they hunt during the park’s higher elevations throughout the entire year, although probably at a reduced level during the winter months, when the prey base is reduced. There is no indication that existing winter activities in the park adversely affect these species. Under the preferred alternative, active winter use in Crater Lake National Park will continue, for the most part, as it has in past years. No expanded winter recreation is proposed under the winter use plan, and the continuation of these activities will not affect threatened or endangered species.