* Clint Walker as Captain Jebediah "Jeb" Dobbs
* Virginia Mayo as Mary Beth "Beth" Tucker
* Russ Tamblyn as "Little" Joe Tucker
* Skip Homeier as "Big" Joe Tucker
* DeForest Kelley as Dr. Samuel "Sam" McCloud
* Richard Anderson as Captain Edward "Ed" Cutler
* Anthony Dexter as Lieutenant "Red" McAlister
* Jim Davis as Sergeant "Sarge" Morgan
* Harry Carey Jr. as "Mountain" Jack
This is the main cast. There are also a number of supporting actors and actresses who appear in smaller roles.