Ida Lupino hired Sam Peckinpah to work on her series "Mr. Adams and Eve (1957)" after she found him living in a shack behind her property. He paid her back by casting her in this film some years later.
Gene Hackman was originally going to play the Joe Don Baker role, but Steve McQueen wouldn't agree to his salary demands and vetoed the casting.
The yellow dog that you see in the movie is the grandson to Spike the dog from the movie "Zanna gialla (1957)."
Preston and Lupino play the parents of Junior Bonner, but both were born in 1918, making them just twelve years older than McQueen.
Sam Peckinpah: for one fleeting shot, passing through the Palace Bar in the film. He appears immediately after Barbara Leigh's friend asks for "Three double bourbons" just before Steve McQueen asks her to dance.