Mount Rushmore National Memorial is a sculpture carved into the granite face of Mount Rushmore near Keystone, South Dakota, in the United States. Sculpted by Gutzon Borglum and later by his son Lincoln Borglum, Mount Rushmore features 60-foot (18 m) sculptures of the heads of former United States presidents (in order from left to right) George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln. The entire memorial covers 1,278.45 acres (5.17 km2) and is 5,725 feet (1,745 m) above sea level. South Dakota historian Doane Robinson is credited with conceiving the idea of carving the likenesses of famous people into the Black Hills region of South Dakota in order to promote tourism in the region. Robinson's initial idea was to sculpt the Needles; however, Gutzon Borglum rejected the Needles site and chose the larger Mount Rushmore. Borglum also decided the sculpture should have a more national focus, and chose the four presidents whose likenesses would be carved into the mountain. After securing federal funding, construction on the memorial began in 1927, and the presidents' faces were completed between 1934 and 1939. Upon Gutzon Borglum's death in March 1941, his son Lincoln Borglum took over construction. Although the initial concept called for each president to be depicted from head to waist, lack of funding forced construction to end in October 1941.