I'd forgotten about "Zandy's Bride." I remember being impressed with it, a slow movie, but a good one in my opinion. The California location was a plus. I agree about "Jeremiah Johnson" and "The Mountain Men." Several of the members of the AMM Party I used to belong to participated in the rendezvous scene. Two movies I only vaguely recall that might have been from our time frame, and don't hold my feet to the fire if I'm wrong, since it's probably been twenty or maybe even thirty years or more since I've seen either of them. One starred Martin Sheen as an ex-soldier/trapper stealing a white horse from an Indian, then having the horse stolen back from him. I remember being impressed with the gear and firearms. The second starred Christopher Walken, carrying a Patterson revolver (again, if I'm remembering it correctly), leading a party after a huge gold wheel, and members trying to double cross one another. (Just looked them up; Martin Sheen's movie was "Eagle's Wing," and the Walken movie was "Shoot the Sun Down," and yeah, I know Sheen's opinion of guns. The reviews called them revisionist Westerns, but I don't recall the themes.)
I appreciate a movie that makes an effort to get the guns and gear correct, but would rather enjoy a good story than nitpick over the gear, as long as it's not too incorrect or over the top.