Tom Horn (film)

Tom Horn is a 1980 Western film about the legendary lawman, outlaw, and gunfighter. It starred Steve McQueen as the title character and was based on Horns own writings.

Cattle company owner John Coble finds Horn in the livery and offers him his ranch to recuperate. He also offers him work investigating and deterring cattle rustlers who steal from the grazing association to which Coble belongs. He implies that the association will support Horn in implementing vigilante justice. Horn accepts the offer and receives the approval of U.S. marshal Joe Belle at an association picnic where he also catches the eye of the local schoolteacher, Glendolene.Calling himself a stock detective, Horn confronts cowboys at an auction whose cattle bear Cobles brand. After giving them fair warning he goes on a one man crusade to kill or otherwise drive off anyone who rustles the cattle of his benefactors. ........

Source: Wikipedia