Natural History of the Black Hills and Badlands
Froiland, Sven G.
The Birds of Wyoming: With an Explanation of Recent Changes in Their Distribution; Economic Aspects
Grave, B.H.; Ernest P. Walker
Mountains and Plains: The Ecology of Wyoming Landscapes
Knight, Dennis H.
Birds of Yellowstone National Park
Western Birds Backyard Guide: Bird Watchers Digest Backyard Guides
Bill Thompson III
Birds of Grand Teton National Park and the Surrounding Area
Ecology of Boreal Owls in the Northern Rocky Mountains.
Hayward, Gregory; Hayward, Patricia; Garton, Edward
Birds of the Northern Rockies
Ulrich, Tom J.
Bird Songs of the Rocky Mountain States & Provinces (3CD)
Righter, Robert W.; Keller, Geoffrey E.
Birds of Wyoming
FAULKNER, Douglas W.
Small Mountain Owls