- The refuge is located in the Missouri Coteau which is composed of intermediate and short grass prairie. It is partly of glacial origin and partly a result of stream erosion by the tributaries of the Missouri River. It is comprised of a 40-50 miles band of rolling glacial hills and rugged river "breaks" located within 10 miles of the Missouri River.
The refuge is an overlay on a sub-impoundment of the Corps of Engineers' Oahe Reservoir project on the Missouri River and managed under a Cooperative Agreement by the Fish and Wildlife Service. The refuge includes upland, marsh and open water habitats.
Birds indigenous to the prairie region can be found on Pocasse. Principal wildlife species include Canada geese, ducks, white-tailed deer, ring-necked pheasant, mink, fox, and beaver. Bald eagles, whooping cranes, sandhill cranes, and peregrine falcons use the area on an occasional basis.
Pocasse NWR is located in north-central South Dakota