3 Best Sights in Custer, Mt. Rushmore and the Black Hills

This 71,000-acre park is considered the crown jewel of South Dakota’s state park system. Elk, antelope, mountain goats, bighorn sheep, mountain lions, wild turkey, prairie dogs, and the second-largest (behind Yellowstone National Park) publicly owned herd of bison in the world roam this pristine landscape. Scenic drives roll past fingerlike granite spires and panoramic views (try the Needles Highway). Take the 18-mile Wildlife Loop Road to see prairies teeming with animals and some of the beautiful backdrops for countless Western films. Accommodations here are outstanding, too, with numerous campgrounds and a resort network that includes five amenities-filled lodges and seven well-appointed vacation cabins.

The park is open year-round, but some amenities are closed over winter.

Jewel Cave's more than 200 miles of surveyed passages made it the third-longest cave in the world as of 2020, while exploration continued. But for tourists who aren't cavers, it's the rare crystalline formations that abound in the cave's passages—not the cave's size—that are the main draw. Take one of the paid, year-round, ranger-led tours, and you'll be rewarded with the sight of tiny crystal Christmas trees, hydromagnesite balloons, and delicate calcite deposits dubbed "cave popcorn." Plan to arrive early in the morning, because summertime tours fill up fast and start at prescheduled intervals. While you wait, scenic surface trails and exhibits in the visitor center can be explored for free.