The battle between the Shoshone and the U.S. cavalry troops riding into an ambush in the Medicine Rock boxed canyon uses footage recycled from the film 'Davy Crockett, Indian Scout' (1950). In that film the same footage is used to depict a battle between Kiowa and U.S. cavalry troops attempting to cross the mountains through the Manitou Pass.
The Ambush Valley attack was clearly from "Kit Carson" (1940).