The other day I posted a story about the 50th anniversary DVD edition of “North by Northwest,” Alfred Hitchcock’s classic movie.

In reading about how the movie was made, I saw conflicting reports about whether any scenes were actually filmed on top of Mount Rushmore National Memorial.

Yesterday I went hunting, and found the definitive story about the flap between Alfred Hitchcock and the National Park Service. And it’s a great story.

So how did Alfie get cooperation from the Park Service officials?

He lied to them.

Or to quote Roger Thornill, the New York advertising executive who is the film’s main character: ” … there’s no such thing as a lie, there’s only the expedient exaggeration.”

According to a very long piece written by Todd David Epp for South Dakota History and posted on the American Experience website, the NPS didn’t want the Four Faces — the real ones or any studio mockups — to be used in scenes involving violence. They thought such scenes would “desecrate” the memorial.

Metro-Goldwyn-Mayer, the studio producing the film, agreed to the NPS terms, in writing. Agreement in hand, the NPS allowed Hitchcock to film scenes in the cafeteria, the parking lot and the viewing terraces. His crew was also allowed to shoot still photos of the mountain carving.

Back in Hollywood, they used the still shots to create life-size studio mockups of the four faces. Then Hitchcock then filmed Cary Grant and Evan Marie Saint in their dramatic and deadly showdown with the commie bad guys — on top of Mount Rushmore.

Later, Hitchcock began leaking stories to the press about the breathtaking chase scene on top of Mount Rushmore.  Everybody loved the idea — except for the NPS officials. They were deeply unamused, but by then there wasn’t much they could do.

Hitchcock and MGM basically chalked it up to a simple misunderstanding.  But I’m sure the NPS guys felt they had experienced something like the closing shot of the film  — “‘Train enters tunnel.”

You can read the whole story here.