* The Last of the Great Scouts: The Life of William F. Cody
* The Enchanted Land: A Study of the History and Folklore of the Southwest
* The Mountains and the Sky
* The Happy Warrior: A Life of George S. Patton
* America's First Wilderness: The Historical Geography of Virginia, Maryland, and Delaware
* The Great American Forest
* The Story of America's National Parks
* The Big Sky: A History of Colorado
* The Southwest: A History of the People
* The River and the Canyon: A History of the Colorado River and Glen Canyon
Essays and Articles
* "The Significance of the Frontier in American History"
* "The American Character"
* "The West in American Literature"
* "The National Parks: A Promise Fulfilled"
* "The Colorado River: A History of Conquest"
* "The Southwest: A Unique Region"
Short Stories
* "The Bear Hunt"
* "The Mountain Man"
* "The Lost Mine"
* "The Ghost Town"
* "The Cattle Drive"
Poetry
* "The Great Plains"
* "The Rocky Mountains"
* "The Desert Southwest"
* "The Grand Canyon"
* "The Pacific Ocean"