Northern Prairie Wildlife Research Center
|46m. Big Sioux Basin||Level IV Ecoregion|
|The Northern Glaciated Plains
ecoregion is characterized by a flat to gently rolling landscape
composed of glacial drift. The subhumid conditions foster a grassland
transitional between the tall and shortgrass prairie. High concentrations
of temporary and seasonal wetlands create favorable conditions for duck
nesting and migration. Though the till soil is very fertile, agricultural
success is subject to annual climatic fluctuations.
The Big Sioux Basin is a trough penetrating the core of the Prairie Coteau (46k). Its topography was affected by pre-Wisconsinan glaciation; later advances of the Wisconsin glacier diverged around the basin. In contrast to the neighboring Prairie Coteau (46k), the basin has a well-developed drainage network. There is more tilled land in the Big Sioux basin due to the relative paucity of wetlands and the gentler topography.
Area (square miles): 1539
Surficial Material and Bedrock
Order (Great Groups)
Precipitation - Mean annual (inches)
Potential Natural Vegetation
Tallgrass prairie: big and little bluestem, switchgrass, and indiangrass, sideoats grama, lead plant. Riparian vegetation: willows and cordgrass north; more hardwoods south.
Land Use and Land Cover
Extensively tilled for small grains, corn, sunflowers, and soybeans.