 New Mexico Territory Governor Lew Wallace(Berton Churchill)sends Deputy Sherif John Steele(John Wayne) into the New Mexico range lands to end the rustling and help the colonization of the savage terriory.Undercover, John hangs around the area s biggest town as a drifter and a drunk.His investigation centers around two factions doing the rustling; Sonora Joe(Luis Alberni),a philosophical and flamboyant stock taker and, the less obvious but more dangerous, cattle-and-land baron Sam Crew(Noah Beery), who poses as a respectable citizen while employing the likes of Arizona Frank Bailey(Paul Hurst)to do his dirty work.News reaches town that a wagon train of settlers with 5,000 head of cattle is on the trail.John joins the pioneers, becoming close friends with the train s leader,Cal Brett(Lafe McKee)and his niece Ginger Malloy(Mae Madison.)Arizona and his men raid the camp and Brett is killed by Arizona in the ensuing gun battle.Sonora Joe and his vaqueros, atop a nearby hill, watch the battle and decide the herd is ripe for their picking.The resourceful John and his marvel horse Duke save the herd.Visiting Sonora s camp the next morning. John reveals his identity and offers to make Sonora a deputy so they might bring Arizoa to justice.The bemused Sonora accepts and assists John in arresting Arizona at the El Dorado saloon and he is sent to Fort Cummings for trial.Crew, determined to get the big herd, has John taken prisoner, and rounds up every gunman in the Valley and rides after the herd.But Duke, not known as the Miracle Horse for nothing,races to Sonora s camp and leads him and his vaqueros to the rescue.This film was a remake of 1927 s "The Land Beyond the Law" and most of the action footage involving John Wayne and Duke in this film is stock footage of Ken Maynard and Tarzan from the 1927 film.