Badlands National Park, in southwest South Dakota, United States preserves 244,000 acres (98,740 ha) of sharply eroded buttes, pinnacles, and spires blended with the largest protected mixed grass prairie in the United States.
A badlands (also badland) is a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. It can resemble malpaís, a terrain of volcanic rock. Canyons, ravines, gullies, hoodoos and other such geological forms are common in badlands. They are often difficult to navigate by foot. Badlands often have a spectacular color display that alternates from dark black/blue coal stria to bright clays to red scoria.