The cavern, which has the usual characteristics of a limestone cave, slopes sharply back from its main entrance, following the dip of the strata. Some of its vaults are decorated in great splendor. The depredations of vandals were so damaging that in 1916 its entrance was closed by an iron gate.
This cavern is the only memorial of the Lewis and Clark expedition in the national parks system; there is no record that the explorers entered it or knew of its existence.
Two hundred and thirty miles east of the Cavern, Clark inscribed his name and the date, July 25, 1806, upon the face of a prominent butte known as Pompey's Pillar. This would have been a far more appropriate monument to the most important of American explorations than the limestone cave. In fact, the Department of the Interior once attempted to have it proclaimed a national monument; the fact that it lay within an Indian allotment prevented. The entire course of this great expedition should be marked at significant points by appropriate national monuments.
Wind Cave National Park
In the southwestern corner of South Dakota, on the outskirts of the Black Hills, is one of the most interesting limestone caverns of the country. It was named Wind Cave because, with the changes of temperature during the day, strong currents of wind blow alternately into and out of its mouth. It has many long passages and fine chambers gorgeously decorated. It is a popular resort.
The United States Biological Survey maintains a game-preserve.
Jewel Cave National Monument
Northwest of Wind Cave, thirteen miles west and south of Custer, South Dakota boasts another limestone cavern of peculiar beauty, through whose entrance also the wind plays pranks. It is called Jewel Cave because many of its crystals are tinted in various colors, often very brilliantly. Under torchlight the effect is remarkable.
Connecting chambers have been explored for more than three miles, and there is much of it yet unknown.