Birds in Place: A Habitat-based Field Guide to Birds of the Northern Rockies
The Birds of El Paso County, Colorado. Part II.
Aiken, Charles E.H. & Edward R/ Warren
A History of the Birds of Colorado
Sclater, William Lutley
A Birder's Guide to Eastern Colorado
Lane, James A.; Holt, Harold R.
The Birds of Denver And Mountain Parks
Niedrach, Robert J.; Rockwell, Robert B.
Report Upon Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian:
Wheeler, Geo. M. & John J. Stevenson
An Annotated List of the Birds of Mesa County, Colorado
ROCKWELL, Robert B.
Seasonal Movement and Habitat Use by Greater Prairie-Chickens in Northeastern Colorado
Schroeder, Michael A.; Clait E. Braun
Birds in Western Colorado
Birds of Colorado's Gunnison Country
Hyde, A. Sidney
American Birding Association Field Guide to Birds of Colorado
Floyd, Ted; Photography by Brian E. Small
Illustrations by Brian E. Small
Western Birds Backyard Guide: Bird Watchers Digest Backyard Guides
Bill Thompson III