Black Elk Peak. Black Elk Peak (formerly Harney Peak) is the highest natural point in South Dakota. It lies in the Black Elk Wilderness area, in southern Pennington County, in the Black Hills National Forest. The peak lies 3.7 mi (6.0 km) WSW of Mount Rushmore. At 7,242 feet (2,207 m), it has been described by the Board on Geographical Names as the highest summit in the United States east of the Rocky Mountains.