The area is the bottom of a sea that covered the area 73 million years ago! The Pierre shale has yielded a vast variety of prehistoric fossils, contains the world's richest Oligocene epoch fossil beds. It has been inhabited by humans for more that 11,000 years. From the Mammoth hunter, followed by, Arikara tribe, Sioux, French fur trappers, miners, hunters, cattle farmers, and homesteaders. Includes sites of 1890s Ghost Dances. Established as Badlands National Monument in 1939, the area was redesignated "National Park" in 1978. Badlands National Park . Half of the admission fee goes to the Oglala Sioux Tribe.
