Stalagmites, stalactites, flowstone, ribbons, columns, helictites, and the "Big Room" are all part of the worthwhile tour into this cave. In 1876, miners found the opening to the cave while digging a flume into the mountainside to carry water to the gold mines below. The cave was opened to the public in 1927, just before the carving of Mt. Rushmore began. In recent years, the attraction added the Soaring Eagle zipline, Gunslinger 7D interactive ride and Xpedition Adventure, a caving adventure tour.