Rushmore Cave 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 1876 when a log flume that supplied water to mining operations in town of Hayward broke and spilled onto the side of the hill. As the water flowed down the hill it started flowing into a small hole in the hillside. The local miners who went up to fix the flume noticed this abnormality and
Mount Rushmore center, finished in 1957. These structures were part of the Mission 66 effort to improve visitors' facilities at national parks and monuments across the country. On October 15, 1966, Mount Rushmore was listed on the National Register of Historic Places. A 500-word essay giving the history of the United States by Nebraska student William Andrew Burkett was selected as the college-age group winner in a 1934 competition, and that essay was placed on the Entablature on a bronze plate in 1973. In 1991, President George H. W. Bush officially dedicated Mount Rushmore. In a canyon behind the carved faces is