In this Gene Autry Western, the valley is threatened by a weed capable of poisoning the cattle. When burning the range proves ineffectual, the local banker, Stacy Bromfield (Frank M. Thomas), sends for a government inspector in desperation. The inspector, played by Autry, quickly suggests spraying the area with a chemical. But the head of the cattlemen's organization, George Larrabee (Robert Homans), foolishly ignores the advice and almost suffers unimaginable consequences when his henchman Frenchy (Hugh Prosser) shoots down a crop duster. Autry, Smiley Burnette, and leading lady Fay McKenzie take time out from battling range weed to warble "Be Honest With Me," "I'll Be True While You're Gone," "Ridin' the Range," "Heebie Jeebie Blues," and the title tune. Sierra Sue was restored in 2001 by Gene Autry Entertainment.