Air Quality
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.
Cultural Resources
As discussed, implementation of the winter use plan would not require construction of structures, roads, or other facilities to support winter recreation. Therefore, implementation of the winter use plan would not affect structures, landscapes, or road and trail segments of historical or cultural significance. Potential impacts on cultural resources caused by implementation of the Development Concept Plan (DCP) will be addressed in the environmental impact statement (EIS) that will be prepared for that project.
Noise
Snowmobile use generates the greatest amount of noise of any winter use activity occurring within the park. Snowmobile use will be confined to the existing route along the north entrance road; as a result, noise impacts resulting from plan implementation are not expected to increase. As discussed, it is the NPS’s intent that the quiet and solitude of the winter backcountry experienced be preserved. Therefore, no additional mechanized equipment, such as trail groomers, will be permitted.
Recreation
Recreation impacts related to overnight camping in the Rim Village area would not occur, because this activity will be prohibited under the preferred alternative. The plan supports maintenance of existing recreational opportunities for snowmobiling, cross-country skiing, snowshoeing, and overnight camping.
