Wildcat Kelly has been dead and buried for years. Or has he? Dale is a reporter for an Eastern magazine who comes West to find out the true story of Kelly, of whom Gabby seems to have mysterious knowledge.

In Roy Rogers' Down Dakota Way, the deadly hoof-and-mouth disease has struck the herd owned by evil rancher H. T. McKenzie (Roy Barcroft). To avoid an expensive quarantine on his stock, McKenzie plans to murder the local veterinarian (Emmet Vogan) before the latter can report his findings to the government. Rogers manages to straighten out the situation by appealing to the sensibilities of the aunt (Elizabeth Risdon) of McKenzie's hotheaded hired assassin (Byron Barr). The film also bears several musical numbers from Roy, Dale Evans, and Foy Willing and the Riders of the Purple Sage.

Diamonds are being smuggled across the border from Mexico in a specially made shoe of a palomino mare. One of the smugglers is killed when the mare runs off. The sheriff blames Trigger for the death. To keep his horse from being destroyed, Roy confesses and goes to jail. The smugglers buy Trigger and put him to work smuggling diamonds. The mare, who had earlier heard a trist with Trigger, foals Trigger, Jr. who Roy, finally out of jail, uses to help capture the smugglers.