WSP09652

• File Number: 8200.765
• Description: White River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 3/1/1994
• Author: USFS
• Title: Snowmass Ski Area - Final Environmental Impact Statement - White River National Forest - Aspen Ranger District - Volume I
• Water Supply Pro - Doc Type: Report/Study

between the Snowmass and Tiehack Ski Areas., Due in large part to its
inaccessibility for recreation, the Main willow Creek drainage is considered to
be the best remaining summer range within the MB-SW. Most of the proposed
expansion area contains summer range of low-to-moderate suitability for elk.
Some lower elevations, however, provide habitat of high suitability during early
summer.

During years with deep snows, winter range represents the most limiting habitat
factor on the MB-SW elk herd. Approximately 11,600 acres (28%) of the big game
LA are classified as winter range. The majority of the winter range is in
private ownership and zoned for some level of development. Approximately 700 elk
from various summer ranges, including those on the PA, use this winter range.

Spring and fall transition ranges used by the MB-SW elk herd are found on the
eastern portion of the permit area and include adjacent private lands as well as
NFSL between the Snowrnass and Tiehack Ski Areas.

The MB-SW elk herd traditionally migrates between winter range, north of the PA,
and summer range, in the Burnt Mountain area, crossing within 0.4 miles on either
side of the Brush Creek-Owl Creek (Glendale) Divide. Private land and ski area
development have significantly reduced the historic elk migration corridor to
approximately ten percent of its pre-development size. '

Veqetative Habitat Tvces

There have been substantial changes in the quantity and distribution of habitat
types since ski resort development began. Most notable are increased acreages
of man-made openings and corresponding decreases in the forested types --
spruce/fir mixed conifer, aspen, and lodgepole pine. Prior to development, a
total of 1,735 acres, of man-made opening existed on the LA, primarily as
agricultural fields. Since then, an additional 2,120 acres of wildlife habitat
have been altered (18 percent of the LA) .

One undeveloped block of natural habitat between the Tiehack and Snowrnass Ski
Areas, approximately 2 . 5 miles wide, remains within the upper Roaring Fork
Valley.' All of the remaining old growth within the LA is located on NFSL in
three blocks of spruce fir/mixed conifer forest -- one directly east of the ridge
that separates the Elk Camp pod from Burnt Mountain, one directly east of the
existing permit area boundary adjacent to mid-Burnt Mountain, and one below
Hanging Valley.

Wetlands and riparian communities are considered to be the habitats which support
the highest densities and diversities of wildlife species. Development
activities which affect these habitats will generally have the most significant
impacts.

2. Environmental Consequences

Elk and Deer

Two scenarios are used to assess potential impacts from NFSL and private land
development on big game habitats. A "Partial Mitigation" Scenario, equivalent
to the scenario assessed in the DEIS, incorporates (1) avoidance and mitigation
of impacts inherent in the design of the range of alternatives, and (2) an
estimate for private land development within the PA, outside of East Village, of
one house every 35 acres. An additional "Full Mitigation" scenario is assessed
at the request of Pitkin County and includes (1) avoidance and mitigation of
impacts inherent in the design of the alternatives, (2) a reduced estimate of
private land development based upon aggressive implementation of 1041
requirements, and (3) implementation of a variety of additional mitigation
measures. The full mitigation scenario is not applied to Alternative E because
its basic design is inconsistent with objectives for additional habitat
protection.

Summary . 16