Badlands National Park

The Lakota named this country mako sica, land bad, and its jagged walls of banded clay and ash erode at a rapid rate of about an inch (2.5 cm) a year. That erosion exposes one of the world's richest beds of fossil mammals, laid down between about 37 and 23 million years ago, including ancient horses, rhinos and saber-toothed predators. Badlands National Park protects about 379 square miles (982 km²) of these formations along with one of the largest undisturbed mixed-grass prairies in the country.

Badlands National Monument was established in 1939 and redesignated a national park on November 10, 1978. The South Unit, also called the Stronghold District, lies within the Pine Ridge Reservation and is co-managed with the Oglala Sioux Tribe. It includes Stronghold Table, where Lakota held Ghost Dances in 1890, and land the military used as a bombing range during World War II. Bison, bighorn sheep and prairie dogs roam the North Unit, and black-footed ferrets, once thought extinct, were reintroduced to the park in 1994.

• South Dakota
  The Mount Rushmore State, plains, badlands, and Black Hills located in
• The Great Plains
  The vast grassland that rises to the Rockies located in
• Mount Rushmore
  The 60-foot presidential faces carved into the Black Hills near
• Wind Cave National Park
  Black Hills park of boxwork caves and bison prairie near
• Pine Ridge Reservation
  Oglala Lakota homeland and the site of Wounded Knee partly in
• Theodore Roosevelt National Park
  North Dakota badlands where a future president became a rancher related