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 also accepted. Historian James Donovan states that when Custer asked interpreter Fred Gerard for his opinion on the size of the opposition, he estimated the force at between 1,500 to 2,500 warriors. Additionally, Custer was more concerned with preventing the escape of the Lakota and Cheyenne than with fighting them. From his own observation, as reported by his bugler John Martin (Martini), Custer assumed the warriors had been sleeping in on the morning of the battle, to which virtually every native account attested later, giving Custer a false estimate of what he was up against. When he and his scouts