Yong Joel Curtis (Ted Donaldson) finds an orphaned colt in the woods, whom he names "Red" and raises and trains him. When he learns that his grandmother (Jane Darwell) is going to have to sell her ranch to pay off the debts, he trains Red, with the help of Andy McBride (Robert Paige), as a race horse with the intention of selling his beloved animal friend in order to pay off his grandmother's debts.

Grandma Aggie, who runs a horse ranch with her orphaned grandson, Joel Curtis, will be forced into a sheriff's sale unless she can raise thousands of dollars in thirty days. Determined to help Aggie, Joel decides to train his stallion, Red, which he has raised from a colt, to race. At the neighboring Moresby Farms, Joel gets ranch hand Andy McBride to convince Mr. Moresby's horse trainer, Ellen Reynolds, to run a test race with Red against Moresby's prize horse, Black Moor. Although Red is fast, he has not been trained to follow the inside rail, and loses. Moresby promises, however, that if Joel can show him a horse that can beat Black Moor, he will buy it from him. As the auction approaches, Joel and his devoted Indian ranch hand, Ho-Na, train Red nightly on the Moresby track with the help of Joel's little dog, Curley. The night before the auction, Ellen and Andy promise Joel that Moresby will take another look at Red in the morning. In the woods, Red becomes entangled in a fight with a bear, however, and is too tired to run. At the sheriff's sale the next day, Red is about to be auctioned, when Joel rides off on him to the Moresby track in time for the race, and beats Black Moor. Granny then convinces Moresby to make Joel a partner in Red's ownership. As Joel hugs Red, Ellen and Andy walk off arm-in-arm, and Granny and Moresby exit the track. Curley then joins the mother of his puppies in the barn.