Badlands National Park, South Dakota, USA

© Dennis Frates/Alam

Baddest of the badlands

Heading west on USA’s Interstate 90 highway, peek out the driver's side as you approach Rapid City, South Dakota, for the first clue you've entered the Wild West: the expansive, layered landscape of Badlands National Park. It's enjoyed government protection since 1939, first as an American national monument and more completely after it was upgraded to US national park status on this day in 1978. The park protects 244,000 acres of dramatically eroded bedrock replete with fossil beds—as well as USA's largest mixed-grass prairie, hosting bison, prairie dogs, and endangered black-footed ferrets.