Roy Rogers and Trigger, "The Smartest Horse in the Movies," enjoy above-the-title billing in Heart of the Rockies. This time, Rogers (playing himself) is pitted against Andrew Willard, a crooked but very powerful landowner, played with relish by
Ralph Morgan. Opposing the construction of a new highway, Willard dispatches his toughest henchmen, headed by Devery (
Fred Graham, one of Hollywood's top stunt men), to prevent the road workers from completing their job. When not duking it out with Devery and his pals, Rogers is kept busy trying to rehabilitate a gang of tough street kids. Penny Edwards plays the heroine, who happens to be the niece of the head villain. The musical portion of the program is provided by the golden-throated Mr. Rogers, together with Foy Willing and the Riders of the Purple Sage. ~ Hal Erickson, All Movie Guide