The Cattlemen is the story of the cattle industry in America and of the men whose ranches reached from the Rio Grande into Montana, from the early Spanish days to Mari Sandoz's contemporary times. It is the second in Sandoz's trilogy of books narrating the history of the American West in relation to animal species.

Mari Sandoz (1896-1966) is the noted author of Old Jules, The Buffalo Hunters, and The Beaver Men: Spearheads of Empire, all available in Bison Books editions. Ron Hull, president emeritus of the Mari Sandoz Heritage Society, is senior advisor to Nebraska Educational Telecommunications and professor emeritus of broadcasting at the University of Nebraska-Lincoln.