Badlands
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Early settlers nicknamed this area in southwestern South Dakota "badlands" because of its rugged landscape that was difficult to traverse on foot. These days, adventure-seekers often bike it instead. Marked by sharp spires of eroded sediment, as well as one of the country's largest grass prairies, approximately half of the park is within the Pine Ridge Indian Reservation. During World War II, parts of Badlands were used by the U.S. military as a practice aerial bombing range (in fact, parts of the South Unit still contain some unexploded munitions). Curious visitors can stop by the Minuteman Missile National Historic Site nearby.

Don't Miss: The Ben Reifel Visitor Center displays many of the fossils found at Badlands, which is a popular destination for paleontologists. In 2010, a young girl found the fossil of a saber tooth cat near the Badlands visitor center that lead to a slew of additional fossil discoveries. The area is now known as the Saber Site.