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
Little Bighorn River Sheep river. The trappers who came to the Big Horn Mountains in the fur trapping era continued the usage of the English translation of the Indian names, and the names for both rivers have come down through history. Captain Reynolds had Jim Bridger as a guide and interpreter, so the information about the source of the name was confirmed by Reynolds from Indian sources through Bridger. According to the USGS, the Little Bighorn River has three other official variants of the name, including Little Horn River, Custer River and Great Horn River. Local people who live in the valley and