Although not remembered as a particularly inventive director, former actor Mack V. Wright manages to wring every drop of excitement from Oliver Drake and Bernard McConville's colorful story, which was not so much based on William Colt McDonald, the creator of The Three Mesqueteers, as on Republic Pictures' flair for making fast-paced action serials. But unlike the chapterplays, the studio spent quite a bit of money on this Western thriller, including expensive location work at St. George, UT, and effective use of glass shots to depict the non-existing "Whistling Skull."