Rushmore Cave into a rock known as limestone. The cave has a cornucopia of rooms including the Entrance Room, Post Office, Image Room, Big Room, Fairyland, Rope Room, Geode Room, The Rouge Room (Party Room), Arrowhead Room, and the Floral Room. The cave also includes boxwork and many dripstone formations including stalactites, stalagmites, columns, helictites and flowstone. Rushmore Cave Rushmore Cave is the closest show cave to Mount Rushmore National Memorial in the United States. It contains a wide variety of natural formations. It is the ninth longest cave in South Dakota. It measures a distance of . It was discovered in
Mount Rushmore of Mount Rushmore", posing for photographs with thousands of tourists. He became one of the most photographed people in the world. The ongoing conservation of the site is overseen by the National Park Service. Physical efforts to conserve the monument have included replacement of the sealant applied originally by Gutzon Borglum, which had proved ineffective at providing water resistance. The components of Borglum's sealant included linseed oil, granite dust, and white lead, but a modern silicone replacement is now used, disguised with granite dust. In 1998, electronic monitoring devices were installed to track movement in the topology of the sculpture