Wind Cave National Park, a unit of the National Park System. It is in southwestern South Dakota on the edge of the Black Hills, near Hot Springs. The park occupies 44 square miles (114 km2) and is named for its most distinctive feature, Wind Cave. The cave was formed in limestone and has numerous passages and rooms, some of which are lined with colorful calcite deposits. Strong air currents that pass in and out of the cave because of changes in atmospheric pressure account for the cave's name.
Within the park is preserved part of the original prairie, consisting mainly of various grasses and wildflowers. Also within the park are many species of animals native to the Great Plains and Black Hills, including bison, elk, deer, pronghorns, and prairie dogs.
Wind Cave is generally believed to have been discovered by Tom Bingham in 1881. It was made a national park in 1903.