 Ron Ormand and Maurice Tombragel politely, quietly, unashamely and without a nod of recognition in the direction of the original writer or film source took a 1937 Republic western with Johnny Mack Brown, "Guns in the Dark" and used it, with only slight changes, as the plot for "Colorado Ranger", and put themselves down for Original Screenplay. At least, they had the good grace not to claim a Story credit. This team made six westerns for Lippert in 1950 starring Jimmy Ellison and Russell Hayden, and all six were "lifted" directly from some A. W. Hackel/Republic film of the 1930 s starring either Johnny Mack Brown or, once, Bob Steele. This one begins with the saloon shoot-out in the dark, just as the Brown film does with the only change being that one member of the trio isn t killed in this version. Shamrock Clark (Jimmy Ellison), Lucky (Russell Hayden), whose character dies early in the four versions that Republic itself used this plot, and The Colonel (Raymond Hatton) escape the shoot-out and head for Cactus Junction, where Sheriff Bradley (Stanley Price), plotting with landowner Morgan (Stephen Carr) to seize the surrounding ranches, brings in Lobo Joe (John Cason) and his gang to get rid of the land occupants. At a homesteader s meeting, ranch owner Ann Green (Julie Adams as Betty Adams) is told that Shamrock, Lucky and the Colonel, who are staying at her place, are wanted outlaws and she returns home and locks them up in the cellar while the Lobo gang goes on a rampage. Shamrock, big surprise, turns out to be an undercover Ranger traveling incognito to investigate Bradley and Morgan s activities.