The Train Robbers (1973)

Three Civil War veterans team up with a train robber's widow to recover a cool half-million in hidden gold. The widow (Ann-Margret), the kind who sticks out in all the right places, wants to clear her husband's name. The three friends (John Wayne, Rod Taylor, Ben Johnson) want the $50,000 reward. But the dead man's ex-partners just want the gold and will kill to get it.