Reva, South Dakota Reva, South Dakota Reva is an unincorporated community in Harding County, South Dakota, United States. Although not tracked by the Census Bureau, Reva has been assigned the ZIP code of 57651. The community has the name of Reva Bonniwell, the daughter of a first settler. The Battle of Slim Buttes occurred here on September 9–10, 1876, in the Great Sioux Reservation between the United States Army and Miniconjou Sioux during the Great Sioux War of 1876. It marked the first significant victory for the Army since the stunning defeat of General George Custer at the Battle of Little Bighorn in
Battle of the Little Bighorn in a series of conflicts known as the Sioux Wars, which took place from 1854-90. While some of the indigenous people eventually agreed to relocate to ever-shrinking reservations, a number of them resisted, at times fiercely. On May 7, 1868, the valley of the Little Bighorn became a tract in the eastern part of the new Crow Indian Reservation in the center of the old Crow country. There were numerous skirmishes between the Sioux and Crow tribes so when the Sioux were in the valley in 1876 without the consent of the Crow tribe, the Crow supported the US Army