Back in 1960, Columbia Pictures released a film called All the Young Men, starring Alan Ladd and Sidney Poitier. It was a war movie, set in Korea, and it tackled the issue of racism in the American armed forces. The film has never made it to DVD, and it's relatively little-known today.
But a portion of All the Young Men was shot in Montana, on the Blackfeet Reservation and in Glacier Park, and the reason for that is interesting. Since it was a war movie set in Korea, Columbia needed lots of extras to play North Korean soldiers ... and they decided the easiest way to do that was to cast Blackfeet Indians in all the Korean roles, and hope no one noticed the difference! Kind of an ironic move for a film designed partly to address the issue of racial stereotypes.
Here's a photo of several of the film's Blackfeet extras, dressed as North Koreans. The shot was taken by Mel Ruder of the Hungry Horse News during the movie's filming in October 1959.