Badlands National Park is in South Dakota. Its dramatic landscapes span layered rock formations, steep canyons and towering spires. These striking geologic deposits contain one of the world’s richest fossil beds. Ancient mammals such as the rhino, horse, and saber-toothed cat once roamed here. The park’s 244,000 acres protect an expanse of mixed-grass prairie where bison, bighorn sheep, prairie dogs, and black-footed ferrets live today.