Mount Rushmore National Memorial, national memorial authorized in 1925. Located in southwestern South Dakota, in the Black Hills, the memorial features the heads of United States presidents George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt carved into a granite bluff. The massive sculpture was carved into the rim of Mount Rushmore 150 m (500 ft) above the valley floor and each face is 20 m (60 ft) tall. The memorial cost nearly $1 million to create. The idea for creating the sculpture in the Black Hills came from South Dakota historian Doane Robinson in the early 1920s. American sculptor Gutzon Borglum designed the memorial and supervised its construction. Borglum envisioned a monument to the growth of the United States and its most important leaders and chose Mount Rushmore as the site. Borglum’s original design was a sculpture of the four presidents down to their waists. Construction of the memorial began in 1927. The head of Washington was completed first, followed by Jefferson and Lincoln. Roosevelt’s head was unfinished when Borglum died in 1941 and his son Lincoln completed the work later that year. Borglum’s studio, located near the memorial, displays plaster models and tools used in creating the statues. Administered by the National Park Service. Area, 517 hectares (1,278 acres).