US government marksmen shot and killed buffalo during production as part of a scheduled herd-thinning. Close observation of the film reveals that the buffalo were shot in the head, which is why they would fall straight to the ground where they were standing.
While filming a scene with Stewart Granger, Anne Bancroft was injured after falling from her horse and was replaced by Debra Paget; in the last sequence, which was apparently not re-filmed, Bancroft can still be easily recognized leaving the cave and starting to descend the mountain.
Since the story takes place during the winter, Stewart Granger wore full winter clothing for his role. However. the movie was filmed during the summer months in Custer State Park in South Dakota. At one point temperatures reached triple digits, Granger passed out from heat exhaustion and the crew had to cut away his clothes to revive him.
This was the first motion picture for Lloyd Nolan in over a year and a half. He had been working on stage in "The Caine Mutiny Court-Martial".
Stewart Granger was charged and nearly killed by a bison while filming. He ran for his life down a fifty-yard embankment but lost his footing and fell, skinning his elbow and cutting his forehead. Lucky for him, the bull turned away at the last second and ran in an opposite direction.