The Cheyenne River Indian Reservation was created by the United States in 1889 by breaking up the Great Sioux Reservation, following its victory over the Lakota in a series of wars in the 1870s. The reservation covers almost all of Dewey and Ziebach counties in South Dakota. In addition, many small parcels of off-reservation trust land are located in Stanley, Haakon, and Meade counties.