Myra Harding, owner of the Harding Ranch, is the latest victim of a ruthless band of rustlers. In desperation, she sends for the State Inspector, whom she has never met but who is reputed to be one of the most fearless men in the country. While out riding the range one day, Myra’s brother Buzzy and his friend, Dude Bates, come across a lost prospector, Ken Blair. They take him back to the ranch, where he is cared for by Myra, who cannot understand why the investigator has not yet arrived. In the meantime, Fred Ames, owner of the neighboring Rolling S ranch, expresses his affection for Myra and his intense dislike of Ken. Ken, having fallen in love with Myra, decides to make his recuperation a slow one, much to Ames’s displeasure. When Buzzy tells Ken that he overheard Fred’s ranch hands boasting that their boss lied about his cattle losses, Ken enlists the boy’s aid in apprehending the rustlers. Ken then rides to the Rolling S, where he discovers that Fred has ordered three high speed trucks to transport the stolen cattle. Ken had suspected that trucks were being used, and with Buzzy’s help, he goes to work and traps the rustlers in their box canyon hideout. Much to the surprise of Myra, Ames is unmasked as the head of the rustlers, and Marshal Ken Blair, who had used the lost prospector identity to get to the ranch in the most inconspicuous manner, is now free to tell Myra that he has won the battle against the thieves but lost his heart to her.