Outlaw Blackie Saunders and his young partner, Sandy, arrive in the small frontier town of Indian Springs to pick up trail supplies. The town's most respected citizen, Parson Jim Wallace, is one of Blackie's former "associates," who is now reformed and has made a new life for himself. When morally outraged citizens attempt to remove the impressionable Sandy from Blackie's custody, the Parson tries mollifying them. This task becomes all but impossible when a crooked deputy robs the express office and Saunders is suspected of the theft.
Some "B" Westerns of the early talkie era took advantage of the new infatuation with dialogue to tell stories that deviated from the genre's tried-and-true conventions by offering more complex characterizations - which were difficult to convey by pantomime alone. Tom Tyler was among the cowboy stars whose first sound pictures included some decidedly offbeat elements and situations. His reformed bad man role in A Rider of the Plains marks a welcome change from the usual cardboard heroics of earlier Tyler vehicles. He receives strong support from character actor Ted Adams, normally cast as a heavy and remarkably effective here as the parson with a past.