Rapid City, South Dakota, the state's second largest city and the seat of Pennington County. It lies at the eastern edge of the Black Hills, 145 miles (233 km) west of Pierre, the state capital. Rapid City is the trading and processing center for a mining and agricultural region that produces gold, wheat, and cattle. Tourism, based on the attractions of the Black Hills, is also important. Educational and cultural institutions in the city include the South Dakota School of Mines and Technology, a Sioux Indian museum, and a geology museum. Ellsworth Air Force Base is nearby.
Rapid City was founded in 1876, two years after gold was discovered in the Black Hills. It was incorporated in 1882. In 1972 the city was devastated by a flash flood that claimed more than 200 lives and caused millions of dollars in damage.