The Mount Rushmore National Memorial is a national memorial centered on a colossal sculpture carved into the granite face of Mount Rushmore in the Black Hills near Keystone, South Dakota, United States. The sculptor, Gutzon Borglum, named it the Shrine of Democracy, and oversaw the execution from 1927 to 1941 with the help of his son, Lincoln Borglum. The sculpture features 60-foot-tall (18 m) depictions of the heads of four United States presidents: George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln, respectively chosen to represent the nation's foundation, expansion, development, and preservation. Mount Rushmore attracts more than two million visitors annually to the memorial park which covers 1,278 acres. The mountain's elevation is 5,725 feet (1,745 m) above sea level.