Bird Pictures by Bill Schmoker: Gallery of high-quality digital photos, mostly from Colorado; tips on digiscoping techniques.
Birding in Colorado: Basic guide to Denver metro area birding hot spots.
Birds of Prey Foundation: Raptor rehabilitation organization based in Boulder County.
Colorado Bird-watching Sites: Guide to 13 sites from National Geographic.
Colorado Birding Society: Recent bird sightings, photo gallery, trip reports, directions to birding spots throughout the state, checklists, report forms, and field trips.
Colorado Field Ornithologists: On-line store, field trips, Colorado Bird Records Committee, checklists, rare bird alert, paper abstracts, journal articles, site guides with maps for 7 spots, report forms, photos and video clips, and bird counts.
Denver Field Ornithologists: Meetings and field trips.
Eckert Crane Days: Annual event held in mid-March in Eckert, to observe the Sandhill Crane migration.
National Wildlife Refuge Bird Checklists: Seasonal checklists for 16 sites in Colorado.
Natural Diversity Information Source - Wildlife Species: Lists of birds, mammals, amphibians, and reptiles for each county.
Rocky Mountain Bird Observatory: Conservation and education projects, volunteer opportunities, Partners In Flight database and bird conservation plan, and news. Formerly Colorado Bird Observatory.
Rocky Mountain Birder: A forum for anyone interested in birding in the Rocky Mountain west.