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 unusually large numbers of Native Americans, Crook held the field at the end of the battle but felt compelled by his losses to pull back, regroup, and wait for reinforcements. Unaware of Crook's battle, Gibbon and Terry proceeded, joining forces in early June near the mouth of Rosebud Creek. They reviewed Terry's plan calling for Custer's regiment to proceed south along the Rosebud while Terry and Gibbon's united forces would move in a westerly direction toward the Bighorn and Little Bighorn rivers. As this was the likely location of native encampments, all army elements had been instructed to converge there