Maureen McClune, owner of the Silver Shadow ranch, runs the "Frontier Week" rodeo every year and needs the financial success of the event to support the ranch. Although the current rodeo is the most profitable in the event's history, Maureen is warned by the rodeo organizers that she must do even better if she wants to get her contract renewed. Her main competition for sponsoring the event is Jack Pomeroy, who owns a rival ranch, as well as a local nightclub and gambling house. When a series of "accidents," apparently caused by negligence, occur during the rodeo, one badly injuring a cowboy in a bronc-busting contest, Maureen's foreman, Gene Autry, must prove his contention that Pomeroy is responsible. That evening, Maureen's aunt Hattie wins some money at a fixed roulette table at Pomeroy's club, thanks to Gene's disabling of the crooked mechanisms. Returning home, they are ambushed by men who Gene knows are Pomeroy's cohorts. Later Gene breaks into Pomeroy's office to get additional proof of his guilt. On the last day of the rodeo, a stagecoach race is scheduled as the final event, with Gene riding against one of Pomeroy's men. Hoping to save the ranch, Aunt Hattie bets everything she has on the outcome. Meanwhile, when Gene discovers his friend, Frog Milhouse, making a recording of a proposal to Hattie, he realizes that Frog's recorder could entrap Pomeroy. He instructs Frog to place the device below Pomeroy's seats at the rodeo just before the start of the race. Although Pomeroy has arranged to have the sheriff think that Gene has committed a murder, Gene escapes, and with Frog's help, is able to make it on time to ride in the race. As Gene rides furiously, almost losing his life, Frog records Pomeroy and his men discussing their part in the disruptions of the rodeo. Finally, Gene wins the race, Hattie wins her bet and Pomeroy and his henchmen are arrested. Freed from their financial worries, Gene and Maureen are free to marry, as are Hattie and Frog.