According to Judi West, director James Goldstone had her voice dubbed, even though she had appeared in numerous films, television shows, and plays, and has more recently taught acting for a number of years.

During filming the cameras recorded two unidentified flying objects: one at Sonora, CA on 11.1.1967; another at Broom Ranch near Camarillo, CA on 12.27.1967. The footage was provided to an investigator from the University of Colorado UFO Project (1966-1968), who determined that the objects were probably some wind-blown debris.

Borden Chase previously wrote The Far Country where the villain was named Gannon.