Shoot, Gringo... Shoot! (1968)

Mexican land-owner Gutierrez offers to save fugitive outlaw Chad Stark from hanging if Stark will agree to find and return Gutierrez' runaway son, Fidel. Stark soon finds Fidel who's joined up with an outlaw band run by Stark's former acquaintance Charlie Doneghan, now calling himself "the Major." Stark tricks the Major into letting him take Fidel to lay the groundwork for a projected train robbery. Stark then forces Fidel on a hazardous journey across a desert where they meet up with the Londonderry family heading west to California. Back at the Gutierrez ranch with the unhappy Fidel, Stark discovers that Fidel is not Gutierrez' son. It seems the woman Gutierrez married was, unbeknownst to him, already pregnant with another man's son. Gutierrez is now determined to avenge his honor by killing Fidel. A shoot-out results with deadly results, especially after the Major arrives on the scene. When the dust settles, Stark heads off to California where he hopes to meet up with the Londonderry's pretty daughter. Joining him is - Fidel.