From Wikipedia: Rio Lobo is a 1970 American Western film starring John Wayne. The film was the last film directed by Howard Hawks, from a script by Leigh Brackett. The film was shot in Technicolor with a running time of 114 minutes. The musical score was composed by Jerry Goldsmith and the movie was filmed at Cuernavaca in the Mexican state of Morelos and at Tucson, Arizona.
It was the third Howard Hawks film varying the idea of a sheriff defending his office against belligerent outlaw elements in the town, after Rio Bravo (1959) and El Dorado (1966), both also starring John Wayne.
Director: Howard Hawks
Writers: Burton Wohl (screenplay), Leigh Brackett
Stars: John Wayne, Jorge Rivero, Jennifer O’Neill