Vegetation Classification and Mapping Project Report - the USGS

USGS-NPS Vegetation Mapping Program
Wind Cave National Park
All of the major geomorphic subdivisions of the Black Hills are represented at WICA and its
immediate surroundings (Froiland 1990). The Central Crystalline Area, made up of granitic and
metamorphic rocks, occurs in the highest, westernmost part of the Park (4,525 - 5,000 feet
elevation). Dramatic topographic relief and rugged slopes characterize this area. East of this
zone is an area underlain by limestones and sandstones, corresponding to the Limestone Plateau
and Minnelusa Foothills regions (4,500 feet elevation). In the project area, the Limestone
Plateau is not well developed due to steep dips of the rock strata (Pahasapa limestone). The
Minnelusa Foothills zone is more extensive including outcrops and narrow limestone-rimmed
drainages such as Limestone and Curley Canyons (Figure 5). Elevations drop through the
Minnelusa Foothills to the Red Valley in the eastern part of the Park. Here, the underlying red,
iron-rich Spearfish formation is intermittently exposed as red badlands or "redbeds" intermingled
with gypsum outcrops (3,610 to 3,770 feet elevation) (Figures 7 and 8). The outermost
geomorphic subdivision is the Dakota Hogback, or Hogback Rim, which is represented in the
project area by Boland Ridge near the east Park boundary (Figure 8). Boland Ridge stands up to
400 ft. above the Red Valley (4,101feet elevation) and is underlain by steeply tilted sandstones.
The eastern side of the Dakota Hogback is gently sloping, while the western slope is generally
steeper and more rugged. The Dakota Hogback represents an interface between the Black Hills
and the Central Great Plains. Finally, broad flat benches capped with old alluvial deposits occur
in the northern and central parts of the study area. Good examples of these benches are located
in northeast WICA between NPS Roads 5 and 6.
Project Area 7