 |
Ecoregions of
|
| 25a. Pine Ridge Escarpment | Level IV Ecoregion |
| Home | The Western High Plains ecoregion
is a landscape of rolling plains and tablelands formed by the erosion
of the Rocky Mountains. Moisture is a limiting factor in the rainshadow
of the Rocky Mountains; as a result, the plains vegetation is dominated
by drought resistant shortgrass prairie. Farming in this region, once
dependent upon rainfall, has been supplemented by irrigation water from
the Ogallala Aquifer.
The Pine Ridge Escarpment forms the boundary between the Missouri Plateau to the north and the High Plains to the south. Ponderosa pine clothe the northern face and the ridgecrest outcrops of sandstone. Cattle graze the rolling grasslands of the Pine Ridge Indian Reservation. A mixed-grass prairie vegetation, rather than shortgrass prairie, dominates this northern extremity of the Western High Plains (25).
Physiography Area (square miles): 965 Geology Surficial Material and Bedrock Soil Order (Great Groups) Climate Precipitation - Mean annual (inches) Potential Natural Vegetation Poderosa pine savannah with eastern redcedar, western snowberry, skunkbush sumac, chokecherry, and rose. Grassland: little bluestem, western wheatgrass, green needlegrass, prairie sandreed. Land Use and Land Cover Cattle grazing, minor hay and feed crops, and some timber cutting. Pine savannah. |
