Movie about a halfbreed native

I think it was in the late 70's when I saw a movie on TV about a halfbreed native guy who starts a rally about getting back some land. All I remember is that he he drove and old beat up truck, he had goofy horse that he called "Itchbum", he put a cop in the hospital after a brawl, and the guy singing the intro to the movie sounded like Kenny Rodgers. The halfbreed guy looked and sounded a little bit like Anthony Quinn, but I'm not sure if that was him.

Try this movie...... Anthony Quinn was in a movie called
FLAP(1970) - It's about Native's trying to take back their land & also
Anthony Quinn had a horse name H-Bomb in the movie.
I'll try to find a link.

Lol! So that's the name of the horse! My dad and my brother even thought it was what I mentioned. That does sound like the movie, and if you can send me a link, that would be nice. Thanks Moviechick!