Ecol ogy of the Black Hills 17the highest point, at Harney Peak (now Black Elk Peak), reaches 2,207 m (7,240 ft.)
and towers 1,500 m (4,920 ft.) above the surrounding prairies. The mountain range is
isolated, being completely surrounded by the Northern Great Plains and covering ap-
proximately 8,400 km^2 (3,240 miles^2 ) (Fecske, Jenks, and Smith 2002). Like the sur-
rounding prairies of South Dakota that are west of the Missouri River, the region was
unglaciated; the Missouri River, centrally located in South Dakota, is about 240 km
(150 miles) east of the Black Hills (Froiland 1990; see fig. 2.2).
The Black Hills ecosystem is diverse and comprises four distinct vegetation
complexes: Rocky Mountain coniferous forest, northern coniferous forest, a grassland
complex, and a deciduous complex. When Custer visited the region in 1874, the pri-
mary forest cover was quaking aspen (Populus tremuloides). Presently, the forest cover
in the Black Hills is predominantly ponderosa pine (Pinus ponderosa), with white
spruce (Picea glauca) and aspen occurring predominately above the 2,000 m contour
(on the limestone plateau) (fig. 2.3).
figure 2.2. Map of the Sioux reservation, created March 18, 2008.
Karl Musser. See https:// commons.wikimedia. org / wiki / File:Siouxreservationmap. png# / media / File:Siouxreservationmap. png.