Badlands National Park
Badlands National Park (Lakota: 'Makȟóšiča') is a national park in southwestern South Dakota that protects 242,756 acres (379.306 sq mi; 98,240 ha) of…
Pierre Shale, Badlands National Park, South Dakota - The black Pierre Shale was deposited between 69 and 75 million years ago when a shallow, inland sea stretched across what is now the Great Plains. Sediment filtered through the seawater, forming a black mud on the sea floor that has since hardened into shale. Fossil clams, ammonites, and sea reptiles confirm the sea environment.