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 by a large force of Sioux who (no longer engaging Reno) rushed down the valley. This was the beginning of their attack on Custer who was forced to turn and head for the hill where he would make his famous "last stand". Thus, wrote Curtis, "Custer made no attack, the whole movement being a retreat". Other historians claim that Custer never approached the river, but rather continued north across the coulee and up the other side, where he gradually came under attack. According to this theory, by the time Custer realized he was badly outnumbered, it was too late to