- State: SD
- NPCA Region: Midwest
- Est. Date: 1908
Air & Climate DataView the Polluted Parks Report
Explorers have mapped more than 192 miles of twisting underground passageways in this cave system and continue to explore more of it each year with no end in sight, making it the third-largest cave in the world. Discover fragile formations of crystal, rock and gypsum during the popular ranger-led tours below ground. Above ground, a series of short trails offer pleasant walks through the park's pine forest, canyons and fields of wildflowers.
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