Badlands & Wind Cave: Prairie to Underground

Two entirely different active experiences in the same Black Hills system — Badlands on the first day for its above-ground geology of eroded clay formations and fossil beds, and Wind Cave National Park on the second day for its extraordinary underground geology. Wind Cave is one of the largest caves in the world by explored length (over 150 miles of mapped passage), and its most unusual feature is boxwork — a honeycomb of thin calcite fins projecting from the cave walls that formed 300 million years ago during a period when the cave was filled with water. Boxwork exists nowhere else in the world in such quantity or quality; Wind Cave has 95% of the world's known boxwork. Above-ground, Wind Cave NP protects one of the largest intact mixed-grass prairies in the world, with a bison herd descended from stock transferred from the last free-ranging population in the 1890s.