Mount Rushmore still disputed on the basis of the 1868 Treaty of Fort Laramie (see section "Controversy" below). Among 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 Charles Rushmore, David Swanzey (husband of Carrie Ingalls), 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 the carving could be accomplished. Borglum had been involved in sculpting the
Mount Rushmore in popular culture in the course of screenwriting, as Hitchcock and scriptwriter Ernest Lehman were struggling to develop an idea. As Lehman would later recall, Hitchcock "murmured wistfully, 'I always wanted to do a chase across the faces of Mount Rushmore.'" While writing the script, Lehman took a trip to Mount Rushmore to scale the faces of the famous monument; he only got halfway to the top, and bought a camera to give to the park ranger to photograph the famous monument for him. However, the scene was not actually filmed at the monument, since permission to shoot an attempted killing on the