Wind Cave National Park in the Black Hills of western South Dakota, established on January 3, 1903, became the world’s first cave protected as a national park and the sixth national park in the United States. Known to Lakota, Cheyenne, and other Native peoples long before that, the cave is sacred in Lakota origin tradition. It is famous for strong airflow at its entrance, rare calcite boxwork, and an immense, exceptionally dense passage system. After its documented discovery by the Bingham brothers in 1881, it developed as a tourist destination. The park also preserves the nation’s largest remaining natural mixed-grass prairie and supports notable wildlife, including a significant free-roaming bison herd.

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Pringle, South Dakota · USA