Keystone, SD

Keystone is a city in Pennington County’s Black Hills, at the base of Mount Rushmore National Memorial. The 2020 census counted 240 residents. South Dakota Highway 16 carries visitors through town toward Mount Rushmore, while the Black Hills Central Railroad’s 1880 Train links Keystone with Hill City on an old gold-hauling line. The town’s streets sit among granite, pine hills, and the tourist businesses that serve the memorial and the surrounding forest. Hill City School District 51-2 serves local students.

Keystone began with hard-rock mining. Fred Cross became its first permanent settler in 1877, a gold claim followed in 1891, and the railroad reached town in 1900. The primary mine closed in 1903, sending the town into a long downturn before work on Mount Rushmore began in 1927. Keystone incorporated on June 8, 1972, one day before a major Black Hills flood damaged the community. The town rebuilt and turned toward visitors, but its mining, railroad, and flood history remain part of the local story. Keystone is a small Black Hills city standing between an old mine town and one of the country’s best-known memorial landscapes.