South Dakota is a Midwestern state in the United States. It is named after the Lakota and Dakota (Sioux) American Indian tribes. South Dakota was admitted to the Union on November 2, 1889. It is one of the six states of the Frontier Strip. South Dakota is comprised of four major land regions: the Drift Prairie, the Dissected Till Plains, the Great Plains, and the Black Hills. The Black Hills are in the southwestern part of South Dakota and extend into Wyoming. This range of low mountains covers 6,000 square miles with mountains that rise from 2,000 to 4,000 feet high. The highest point in South Dakota, Harney Peak, is in the Black Hills. The Black Hills are rich in minerals such as gold, silver, copper, and lead. The Homestake Mine, one of the largest gold mines in the United States, is located in the Black Hills.