Ranch owner Cyclone Kenyon can't get the hired hands to work because they spend too much time serenading his flirtatious granddaughter, Betty Lou. Her older sister, Dale, fires the boys and engages a bunch of female wranglers. To get even, Betty Lou persuades two shifty cowboys to masquerade as horse thieves. She is unaware that the villainous duo intends to really steal the horses and lay the blame on her. Roy Rogers sets out in pursuit of the rustlers determined to restore the missing herd.
This 1944 Republic horse opera features Roy Rogers in his "King of the Cowboys" phase, during which his starring vehicles emphasized music and comedy. San Fernando Valley is a contemporary Western, with sophisticated swing-era songs, several of them exuberantly vocalized by pint-sized Jean Porter. In their fourth film together, Roy and Dale amply exhibit the star chemistry that made them a successful team beyond the "B"-Western era into the early years of television. - Ed Hulse