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
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.
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 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
Under Alternative 2, the potential for impacts on water
resources would be less because the use of mechanized snow machines would not be
permitted in the park, and backcountry use would be restricted to day use. While
there is no evidence indicating that existing activities affect surface water
resources, eliminating these uses from the park would reduce potential impacts.
There is no indication that existing winter activities in Crater
Lake National Park adversely effect wildlife species. However, it is assumed
that reduced winter use would have a positive effect on species inhabiting the
north area of the park or the backcountry areas frequented by overnight campers.
Eliminating the use of mechanized snow machines in the park
would eliminate snow machine exhaust emissions. Existing emissions do not
generate a noticeable air quality impact in the park. If snowmobile use were
eliminated, exhaust emissions related to these machines would be eliminated.
Although this would likely not result in a noticeable change in air quality,
short-term odors and irritants associated with snow machine exhaust would not
Soils and Vegetation
No impacts on soil or vegetation occur during the winter season
under existing conditions, because snowmobiles are required to stay on road
corridors, and because campfires in the backcountry are prohibited. Reduced
winter use would not have an impact on soils and vegetation.
Threatened and Endangered Species
While there is no evidence indicating that winter activities
have an impact on threatened and endangered species in the park, reduced winter
use would lessen impact potential. Eliminating snowmobiling and backcountry
camping from the park would reduce noise and decrease human presence in the
north entrance area and in the park's backcountry. It is assumed that the
reduced potential for impact would benefit any threatened or endangered species
in the area.
No cultural resources are affected by existing winter use.
Reducing winter use would have no affect on the park's cultural resources.
Eliminating the use of snowmobiles in the park would reduce
existing intermittent noise levels in the northern portion of the park. As
discussed in the winter use plan, a major objective of the NPS is to preserve
the quiet and solitude of the park's backcountry areas while providing access to
all user groups.
Under this alternative, winter recreation opportunities in
Crater Lake National Park would be reduced. Snowmobiling and overnight
backcountry camping would be eliminated. As data show, the number of visitors
using backcountry areas during the winter is increasing. Eliminating overnight
backcountry camping would have an impact on users visiting the park for this
reason. In addition, eliminating snowmobile use would also have an impact on
those visitors entering the park by snowmobile via the north entrance road.
Alternative 3 - Expanded Cross-Country Skiing
Impacts on water resources would be similar to those described
for Alternative 1. The impacts on water resources (e.g., Annie Creek) from
development in Mazama Village would be addressed in the EIS being prepared for
Under this alternative, impacts on wildlife resources would be
similar to those described for the winter use plan, with the exception that
intermittent disturbances could occur in Mazama Village with expanded use of
this area. It is unlikely that increased crosscountry skiing opportunities in
the rim area would affect wildlife, because those few species active during the
winter months are accustomed to intermittent human activity.
Impacts would be similar to those described for Alternative 1.
Soils and Vegetation
No impacts on soils and vegetation would occur under this
Threatened and Endangered Species
Impacts on threatened and endangered species would be similar to
those described for Alternative 1. If Mazama Village were to be developed,
impacts on threatened and endangered species in the Mazama area would be
evaluated in the DCP EIS.
Impacts on cultural resources would be the same as those
described for Alternative 1. However, if Mazama Village were to be developed,
impacts on cultural resources in this area would be addressed in the DCP EIS.
Noise impacts associated with this alternative would be similar
to those described for Alternative 1. It is not anticipated that noise impacts
under this alternative would affect the quiet and solitude experienced in Crater
Lake National Park's backcountry since crosscountry skiing is not an activity
that generates a high level of noise.
No impacts on recreation would occur under this alternative.
Development of the Mazama Village area would increase recreation opportunities
in the park. The presence of support facilities would further increase park
Alternative 4 - Expanded Snowinobiling and Cross-Country Skiing
Increased use of mechanized snow machines in the park would
increase the potential for impacts on water resources. An incremental increase
in the release of pollutants such as petroleum products would be anticipated
under this alternative. Use of snow machines and trail grooming equipment on the
Pinnacles road would increase the potential for impacts on Wheeler Creek.
Cross-country ski trail grooming equipment would also increase the potential for
impacts downslope of groomed trail areas.
Wildlife impacts under this alternative would be similar to
those described under Alternative 3. However, periodic short-term disturbance to
wildlife could occur near Rim Drive when mechanized trail grooming equipment
operates in this area.
Increased use of mechanized snow machines in the park for trail
grooming and pleasure trips would increase overall emissions. However, it is
difficult to predict whether emissions would cause a noticeable air quality
impact. Cross-country skiers and other backcountry users may become more aware
of snowmobile exhaust, thereby reducing the user experience for those winter
activities. In addition, exhaust from mechanized trail groomers may impact
cross-country skiers on East Rim Drive.
Soils and Vegetation
Impacts on soils and vegetation would be similar to those
described for Alternative 1. Although activity in the park would likely
increase, trail grooming and snowmobile use would occur in existing road
Threatened and Endangered -Species
Under this alternative, cross-country skiing and snowmobiling
would increase around and southeast of the rim. During the winter months,
peregrine falcon activity in the park is limited to perching, foraging, and
occasional feeding on whatever avian prey is available. According to Johnsgard
(1990), peregrine falcon prey includes rock and mourning doves, gray jays,
waterfowl, and microtines (voles) during years of abundance. According to
Follett (1979), only the gray jay is commonly present during the winter months.
Although no data are available, peregrine falcon use of the park during the
winter months is most likely low, with wintering activity primarily in the
snow-free lowland areas outside the park where prey is in greater abundance
(e.g., Klamath Lake).
Given the relatively minor increases in use that would occur
under this alternative (groomed cross-country ski trails along portions of the
rim and an additional 6 one-way miles of snowmobile trail), this alternative
would not have a significant adverse impact on threatened or endangered species.
No impacts on cultural resources would occur under this
Noise impacts would increase with the use of mechanized snow
machines along the Pinnacles road. Increased noise would disrupt the quiet and
solitude of the existing Crater Lake backcountry experience. This impact would
be inconsistent with Management Objective 4, which seeks to maintain the quiet
and solitude of the backcountry areas by minimizing use of motorized, over-snow
Recreation opportunities would increase for snowmobilers and
cross-country skiers under this alternative. An additional snowmobile route
along the Pinnacles road, along with groomed ski trails along portions of Rim
Drive, would increase recreation opportunities for both user groups.
Implementation of the proposed winter use plan would not cause
significant impacts on elements of either the built or natural environment. As
described, impacts associated with implementation of the winter use plan
alternatives would, in some cases, increase the potential for environmental
impacts and an associated degradation in the winter backcountry experience. As
discussed, environmental impacts associated with DCP development activities will
be addressed in the EIS presently being prepared for the DCP.
No significant cumulative impacts from implementation of the
winter use plan together with other actions such as the DCP are anticipated.
Because this plan does not support or encourage new activities or increased use
levels for existing activities, environmental issues associated with development
of additional facilities will be evaluated in future documents.