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
Bury My Heart at Wounded Knee Hills, angering the Lakota and Dakota living there. A peace council in 1875 tried to arrange for the US government to either purchase the mineral rights or outright ownership of the Black Hills, but both proposals were rejected by the Sioux. In 1876, a series of battles occur between the Sioux and US troops which initially ends when the Sioux defeat General Custer and his troops at the Battle of Little Bighorn on June 25. The humiliated US Army sends a peace council to sign a treaty that forces the Sioux out of the Black Hills to the Missouri River.