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 battle. Custer had initially wanted to take a day and scout the village before attacking; however, when men went back after supplies dropped by the pack train, they discovered they were being back-trailed by Indians. Reports from his scouts also revealed fresh pony tracks from ridges overlooking his formation. It became apparent that the warriors in the village were either aware of or would soon be aware of his approach. Fearing that the village would break up into small bands that he would have to chase, Custer began to prepare for an immediate attack. Custer's field strategy was designed to