Yet another Roy Rogers Western whose title refers to a song, In Old Amarillo actually takes place in and around Amarillo of 1951. Fired by cattleman George Hills (Minor Watson), foreman Clint Burnside (Roy Barcroft) plans to avenge himself by ruining Hills' wastrel son, Philip (Ken Howell). Along with local saloon owner Mike Carver (William Holmes), Burnside is also attempting to buy up all the area's ranches during a prolonged drought. When Roy Rogers, Hills' new foreman, suggests that the ranchers come together and use modern rainmaking equipment, including airplanes armed with dry ice, Burnside and Carver lure Philip into committing a bit of sabotage. At first Roy accuses the young man of shooting down the rainmaking aircraft but then discovers that he was forced to pilot the attacking plane by Burnside, the real killer, who is himself killed in a climactic fistfight.