The movie is based upon Across the Wide Missouri, a historical work by Bernard DeVoto, which was was awarded the Pulitzer Prize for History in 1948. Set in the 1930's, this is the fictional story of beaver trapper Flint Mitchell, played by Clark Gable and his adventures with the other trappers and the Indians in Montana and Idaho. A narration was added and the movie was edited from 135 minutes to 76 by MGM executives after the film failed before test audiences. Director William Wellman disowned the film after the editing.
Flint plans to marry a Blackfeet girl, who had been kidnapped and raised by the Nez Perce. Flint thinks if he returns her to her father, who is a Blackfeet chief, he will let him and his men trap their rich lands. Flint says "She can't do me any harm and she may do me a lot of good." Flint is only in it for the money.
As Flint comes to know his wife, Kamiah, he begins to fall in love. He says to her "You're full of magic...the one woman in the world for me and I love you, pigeon. Maybe I didn't know it when I found you but I know it now. You can't understand what I'm trying to tell you and I don't understand much you say. Someday, maybe. The narrator later says "My father told me that for the first time, he saw these Indians as he had never seen them before - as people with homes and traditions and ways of their own. Suddenly they were no longer savages. They were people who laughed and loved and dreamed."
When they entered the Blackfoot land they were ambushed by Ironshirt, a young Blackfoot prince, who thought the land was Blackfoot, and he wanted it kept that way. He considered trappers to be intruders and enemies who should be hunted and killed. Flint manages to escape from Ironshirt, but not before killing one of his braves.
Flint brought Kamiah back to see her grandfather, and he was under his protection. Flint and Kamiah have a baby boy. Everything was going well until a trapper seeking revenge for the death of his brother kills a Blackfoot chief. Now Ironshirt becomes the new chief.
When Ironshirt and his braves attacks the trappers, Kamiah is killed. The baby is on a pouch on a horse and the horse takes off during the attack. Ironshirt follows after the baby and Flint goes off after both of them and ends up killing Ironshirt, and saving his son.
Interesting movie, that allows you to see Ironshirt as a patriot and a hero, even though he is of course sacrificed in the interests of box office receipts. The narration then goes on to talk of the heroism of the trappers in opening up the West to new travelers and new "understanding" they created, whatever that means.
Overall, a good movie with really good camp and trapping scenes. Beautifully filmed. A little choppy, with all the editing, and probably nowhere as good as it originally was, but still a pretty good movie.