The waters of the sandhills region in Nebraska drain into the Platte River system. It is a major source of sediment for some of the ecosystem. This region developed from wind-deposited sand after the close of the last glacial epoch. Topography consists of rolling steep-sided slopes with level to slightly sloping valleys between the sand dunes.
Soils are very sandy, well-drained, and vary in texture from loamy fine sand to fine sand.
Typical forbs are silky prairie clover, hoary puccoon, annual eriogonum, prairie coneflower, stiff sunflower, prairie sandwort, and little pricklypear. Leadplant, New Jersey tea, wild rose, western snowberry, and soapweed yucca are the principal shrubs of this community. The mixed prairie community exists on nearly level terrain both north and south of the Platte River. Because of its topography, most of the mixed prairie has been converted to agricultural production. Soils are deep silty loams derived from loess deposits.