 By early 1959 the project had become a vehicle for Clint Walker, the star of Warner Bros' hit TV show "Cheyenne" and the final script was done by Burt Kennedy who was under contract to Warners at the time.Walker's co-star was Edd Byrnes who had leapt to fame playing "Kookie" on the Warner Bros detective show "77 Sunset Strip".Filming took place in April and June 1959, partly on location in Flagstaff, Arizona.