Mountain Press Publishing Company
- Roadside Geology of New York
- Roadside Geology of Minnesota
- Roadside Geology of Alaska
- Roadside Geology of Northern California
- Roadside Geology of the Yellowstone Country
- Roadside Geology of Virginia
- Northwest Exposures
- Cow Country (Tumbleweed)
- Big-Enough (Tumbleweed)
- Roadside Geology of Indiana
- Scorpion, a Good Bad Horse
- The Color of Horses
- Ice Age Mammals of North America
- Organic Gardening in Cold Climates
- The Saga of the Pony Express
- Roadside Geology of Massachusetts
- Geology Underfoot Along Colorado's Front Range
- The American Cowboy
- From Earth to Herbalist
- Roadside Geology of Ohio
- The Bristlecone Book
- The Drifting Cowboy
- Horses I've Known
- Geology Underfoot in Yosemite National Park
- The Long Rifle
- Raptors of the West
- Roadside History of Arizona
- Roadside Geology of Montana
- Roadside Geology of New Mexico
- Roadside Geology of Utah