John Wayne as Col. Cord McNally

Jorge Rivero as Capt. Pierre Cordona

Jennifer O'Neill as Shasta Delaney

Jack Elam as Phillips

Christopher Mitchum as Sgt. Tuscarora Phillips

Victor French as Ketcham

Susana Dosamantes as Maria Carmen

Sherry Lansing as Amelita

David Huddleston as Dr. Ivor Jones

Mike Henry as Rio Lobo Sheriff 'Blue Tom' Hendricks

Bill Williams as Blackthorne Sheriff Pat Cronin

Jim Davis as Riley

Dean Smith as Bide

Robert Donner as Whitey Carter

George Plimpton as George, Whitey's 4th Henchman

Edward Faulkner as Lt. Harris

Peter Jason as Lt. Ned Forsythe

Chuck Courtney as Chuck, Whitey's 2nd Henchman

Robert Rothwell as Whitey's 3rd Henchman

Don 'Red' Barry as Feeny - Bartender (uncredited)

Sondra Currie as Blackthorne Prostitute (uncredited)

Chuck Hayward as (uncredited)

Conrad Hool as Bart (uncredited)

Lance Hool as Picket (uncredited)

John Hudkins as Rio Lobo Deputy (uncredited)

Michael Jeffers as Barfly in Blackthorne (uncredited)

Frank Kennedy as Minor Role (uncredited)

Richard LaMarr as Man in Army Post Saloon (uncredited)

John McKee as Rio Lobo Deputy (uncredited)

Boyd 'Red' Morgan as Train Engineer (uncredited)

William H. O'Brien as Man in Army Post Saloon (uncredited)

Gregg Palmer as Pete - Henchman (uncredited)

Jim Prejean as Union Soldier (uncredited)

Rudy Robbins as Man (uncredited)

Chuck Roberson as Corporal in Baggage Car (uncredited)

Danny Sands as Man Delivering Message to Jail (uncredited)

Cap Somers as Card Player (uncredited)

Bob Steele as Rio Lobo Deputy (uncredited)

Tommy Tedesco as Guitar Player in Opening Credits (uncredited)

Ethan Wayne as Boy (uncredited)

Hank Worden as Hank - Hotel Clerk (uncredited)