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
Little Bighorn River battle by the History Channel. The alternative name usage in the 1800s by the Sioux, Cheyenne and Crow of "Greasy Grass" for the "Little Bighorn" is reflected in current day nomenclature at the Little Bighorn battlefield. A prominent ridge on the Little Bighorn Battlefield that overlooks the eastern banks of the Little Bighorn River has retained the name of Greasy Grass Ridge, and is the site of critical events of the battle. In Lakota, the Little Bighorn River is called . Upstream from the point where the Little Bighorn issues from the Little Horn Canyon canyon, the stream flow is