Mount Rushmore National Memorial, near Keystone, South Dakota, is a monumental granite sculpture located within the United States Presidential Memorial that represents the first 150 years of the history of the United States of America with 60-foot (18 m) sculptures of the heads of former United States presidents: George Washington (1732-1799), Thomas Jefferson (1743-1826), Theodore Roosevelt (1858-1919), and Abraham Lincoln (1809-1865). The entire memorial covers 1,278 acres (5.17 km²), and is 5,725 feet (1,745 m) above sea level. It is managed by the National Park Service, a bureau of the United States Department of the Interior. The memorial attracts approximately 2 million people annually.
Originally known to the Lakota Sioux as Six Grandfathers, the mountain was renamed after Charles E. Rushmore, a prominent New York lawyer, during an expedition in 1885. At first, the project of carving Rushmore was undertaken to increase tourism in the Black Hills region of South Dakota. After long negotiations involving a Congressional delegation and President Calvin Coolidge, the project received Congressional approval. The carving started in 1927, and ended in 1941 with a few injuries and no deaths.
As Six Grandfathers, the mountain was part of the route that Lakota leader Black Elk took in a spiritual journey that culminated at Harney Peak. Following a series of military campaigns from 1876 to 1877, the United States asserted territorial control over the area, a claim that is still disputed on the basis of the 1868 Treaty of Fort Laramie (see Controversy below). Among white American settlers, the peak was known variously as Cougar Mountain, Sugarloaf Mountain, Slaughterhouse Mountain, and Keystone Cliffs. It was named Mount Rushmore during a prospecting expedition by Rushmore, David Swanzey (whose wife Carrie was the sister of author Laura Ingalls Wilder), and Bill Challis.
Historian Doane Robinson conceived the idea for Mount Rushmore in 1923 to promote tourism in South Dakota. In 1924, Robinson persuaded sculptor Gutzon Borglum to travel to the Black Hills region to ensure that the carving could be accomplished. Borglum had been involved in sculpting a massive bas-relief memorial to Confederate leaders on Stone Mountain in Georgia but was in disagreement with the officials there. The original plan was to perform the carvings in granite pillars known as the Needles. However, Borglum realized that that plan was impossible because the eroded Needles were too thin to support sculpting. He chose Mount Rushmore, a grander spot, partly because it faced southeast and enjoyed maximum exposure to the sun. Borglum said upon seeing Mount Rushmore, "America will march along that skyline." Congress authorized the Mount Rushmore National Memorial Commission on March 3, 1925. President Coolidge insisted that along with Washington, two Republicans and one Democrat be portrayed.
Between October 4, 1927 and October 31, 1941, Gutzon Borglum and 400 workers sculpted the colossal 60-foot (18 m) carvings of U.S. presidents George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln to represent the first 150 years of American history. These presidents were selected by Borglum because of their role in preserving the Republic and expanding its territory. The image of Thomas Jefferson was originally intended to appear in the area at Washington's right, but after the work there was begun, the rock was found unsuitable, so this figure was moved to Washington's left.
In 1933, the National Park Service took Mount Rushmore under its jurisdiction. Engineer Julian Spotts helped with the project by improving its infrastructure. For example, he had the tram upgraded so that it could reach the top of Mount Rushmore for the ease of workers. By July 4, 1934, Washington's face had been completed and was dedicated. The face of Thomas Jefferson was dedicated in 1936, and the face of Abraham Lincoln was dedicated on September 17, 1937. In 1937, a bill was introduced in Congress to add the head of civil-rights leader Susan B. Anthony, but a rider was passed on an appropriations bill requiring that federal funds be used to finish only those heads that had already been started at that time. In 1939, the face of Theodore Roosevelt was dedicated.
The Sculptor's Studio—a display of unique plaster models and tools related to the sculpting—was built in 1939 under the direction of Borglum. Borglum died from an embolism in March 1941. His son, Lincoln Borglum, continued the project. Originally, it was planned that the figures would be carved from head to waist, but insufficient funding forced the carving to end. Borglum had also planned a massive panel in the shape of the Louisiana Purchase commemorating in eight-foot-tall gilded letters the Declaration of Independence, U.S. Constitution, Louisiana Purchase, and seven other territorial acquisitions from Alaska to Texas to the Panama Canal Zone.
The entire project cost USD$989,992.32. Notably for a project of such size, no workers died during the carving.
On October 15, 1966, Mount Rushmore was listed on the National Register of Historic Places. An essay from Nebraska student William Andrew Burkett, selected as the winner for the college-age group in 1934, 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 a chamber, cut only 70 feet (21 m) into the rock, containing a vault with sixteen porcelain enamel panels. The panels include the text of the Declaration of Independence and the Constitution, biographies of the four presidents and Borglum, and the history of the U.S. The chamber was created as the entrance way to a planned "Hall of Records"; the vault was installed in 1998.
Ten years of redevelopment work culminated with the completion of extensive visitor facilities and sidewalks in 1998, such as a Visitor Center, Museum, and the Presidential Trail. Maintenance of the memorial annually requires mountain climbers to monitor and seal cracks. The memorial is not cleaned to remove lichens. It has been cleaned only once. On July 8, 2005, Kärcher GmbH, a German manufacturer of cleaning machines, conducted a free cleanup operation; the washing used pressurized water at over 200 °F (95 °C).