The U. P. Trail by Zane Grey

Classic Western. U.P. stands for Union Pacific. The book begins: In the early sixties a trail led from the broad Missouri, swirling yellow and turgid between its green-groved borders, for miles and miles out upon the grassy Nebraska plains, turning westward over the undulating prairie, with its swales and billows and long, winding lines of cottonwoods, to a slow, vast heave of rising ground -- Wyoming--where the herds of buffalo grazed and the wolf was lord ... According to Wikipedia: Zane Grey (1872 – 1939) was an American author best known for his popular adventure novels and stories that presented an idealized image of the rugged Old West. As of June 2007, the Internet Movie Database credits Grey with 110 films, one TV episode, and a series, Dick Powells Zane Grey Theater based loosely on his novels and short stories.