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
Goes Ahead Sioux and Cheyenne who were expected to be on either Rosebud Creek or in the Little Bighorn valley. The six Crow scouts were sent with Custer because they were familiar with the Rosebud and Little Big Horn drainage. On June 24, 1876 the Crow scouts were ranging ahead, and they sent back word to Custer that the trail of the Sioux/Cheyenne encampment had moved from the Rosebud valley toward the valley of the Little Bighorn. At first light on June 25, 1876, the morning of the battle, the Crow scouts were at a high point (later known as the Crows