How Did “North by Northwest” Achieve the Look of Filming on the Face of Mt. Rushmore?
The only authentic shots of Mt. Rushmore in North by Northwest (1959) are the ones looking at the monument from a distance. The shooting and subsequent ambulance scenes were filmed in the actual monument cafeteria and surrounding grounds, but nothing that required accessing the monument itself was on-location.
While Hitchcock did have an original permit to film on and around the mountain, rumor got out that the film involved a fight scene and a couple deaths on the face of the monument, and government officials banned the production from filming there. Mt. Rushmore had to be recreated on a Hollywood set.
Shooting the scenes on the MGM Mt. Rushmore was as simple as any other Hollywood trickery using set pieces, special effects, and clever camera work.