After suffering a great personal loss, 25-year-old Theodore Roosevelt abandons New York for the wild frontier. In the lawless Dakota Badlands, he establishes the sprawling Elkhorn Ranch and attempts to remake himself into a cattleman.
Theodore Roosevelt's newly built Elkhorn Ranch is threatened by a powerful neighbor who attempts an underhanded land grab. To save his ranch, Roosevelt must confront his neighbor, the Marquis de Morés, and his beguiling wife, Medora.
Theodore Roosevelt's efforts to become a cattleman are jeopardized when a neighboring rancher accuses his men of rustling cattle. To save Elkhorn's reputation, Roosevelt and his men must capture the thief and return the stolen livestock.
After Theodore Roosevelt's new horses are stolen, he joins a posse of vigilantes to hunt down the thieves. When they capture a lone outcast who swears his innocence, Roosevelt learns firsthand that frontier justice isn't always just.
Just as Theodore Roosevelt is finally getting his cattle operation up and running at Elkhorn Ranch, his health takes a turn for the worse, and his trusted ranch manager must race to a Sioux village to find a cure before it's too late.
Looking for a distraction from his tasks at Elkhorn Ranch, Theodore Roosevelt decides a hunting expedition to the Bighorn Mountains of Wyoming might settle his mind, but he soon finds himself face to face with a man-eating grizzly bear.