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 relieve pressure on Reno's detachment (according to the Crow scout Curley, possibly viewed by both Mitch Bouyer and Custer) by withdrawing the skirmish line into the timber on the edge of the Little Bighorn River. Had the U.S. troops come straight down Medicine Tail Coulee, their approach to the Minneconjou Crossing and the northern area of the village would have been masked by the high ridges running on the northwest side of the Little Bighorn River. That they might have come southeast, from the center of Nye-Cartwright Ridge, seems to be supported by Northern Cheyenne accounts of seeing the approach