Frank Harris is a Chicago hotel clerk with dreams of becoming a cowboy. He falls in love with Maria Vidal, the daughter of a wealthy Mexican cattle baron, but finds his advances rejected due to their different social statuses. Determined to prove himself, Frank gets an unexpected opportunity when seasoned trail boss Tom Reece arrives at the hotel. In a twist of fate, Frank helps Reece win back his gambling losses and convinces him to let him join his cattle drive to Mexico. Frank's naive romanticism and lack of experience soon clash with the harsh realities and strenuous demands of life on the trail.

As the journey progresses, Frank discovers the complexities of cowherding, facing dangers like stampedes, rough terrain, and conflicts with bandits. He tries to earn the respect of the other cowhands while grappling with his feelings for Maria and his evolving relationship with Reece, who becomes a tough but reluctant mentor. Through grit and determination, Frank gradually learns the skills and resilience required to be a true cowboy, undergoing a transformative journey that tests his character and resolves his deepest desires.