One of the world's longest and most complex caves lies beneath a bison and prairie dog-filled South Dakota grassland.
May–September for the full tour schedule; the cave stays about 53°F year-round.
Summer cave tours often sell out by midday, so get tickets early.
Prairie storms bring hail and lightning in summer, and winters are cold and windy.
General patterns — conditions vary by year. Check current NPS alerts and road status before you go.
Distances are rough estimates to the closest entrance. Check road and ferry conditions before you go.
Campgrounds inside the park are booked through Recreation.gov, and many fill months ahead.
FIND CAMPSITES ON RECREATION.GOV ↗There’s no lodging inside this park, so most visitors stay in the nearby towns above.