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Northern Prairie Wildlife Research Center

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Ecoregions of
North Dakota
South Dakota

47. Western Corn Belt Plains

47a. Loess Prairies Level IV Ecoregion


North Dakota Ecoregions

South Dakota Ecoregions

47a. Loess Prairies

47d. Missouri Alluvial Plain

  The high agricultural productivity of the Western Corn Belt Plains ecoregion is due to its fertile soil, temperate climate, and adequate precipitation during the growing season. This ecoregion has a relatively homogeneous topography of level to gently rolling glacial till plains with areas of morainal hills and loess deposits. The original tallgrass prairie vegetation has been converted to intensive rowcrop agriculture of corn, soybeans, and feed grains to support livestock production.

JPG - Aerial view of terracing and contouring
Contouring and terracing are common practices in the loess-covered areas of the Western Corn Belt Plains.

The Loess Prairies of Iowa and South Dakota surround the perimeter of the Des Moines lobe of the Late Wisconsinan glaciation. Of the two areas in South Dakota, the northern one is distinguished from neighboring regions by its rock-free soil and a paucity of wetlands. The southern area is more highly dissected, with deciduous woodland and brush on the steeper slopes and in the draws.


Area (square miles): 1104

Elevation/Local Relief (feet): 1200-1700/40-120

Gently rolling in the northern section, more dissected in the southern section. Streams have a quartzite substrate providing diverse habitat for aquatic life.


Surficial Material and Bedrock
Loess deposits over Cretaceous sandstone, shale (Niobrara Formation and Carlile Shale), and Sioux quartzite.


Order (Great Groups)
Mollisols (Haplustolls)

Common Soil Series
Moody, Nora, Trent

Temperature/Moisture Regimes


Precipitation - Mean annual (inches)

Frost Free - Mean annual (days)

Mean Temp. - Jan. min/max; July min/max, (°F)

Potential Natural Vegetation

Tallgrass prairie: big and little bluestem, indiangrass, green needlegrass. In southern section on steeper slopes needleandthread and prairie dropseed, and deciduous woodland.

Land Use and Land Cover

Intensive row crop agriculture (corn, soybeans, alfalfa, grain sorghum). Some terracing. Some urban development. Deciduous woodland in the southern section.

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