The Allen's Hummingbird is common only in California. It is similar to a Rufous Hummingbird, but it has a green back.
Breeding area in the United States :
Map courtesy of Patuxent Wildlife Research Center, United States Department of the Interior, Laurel, MD. From THE NORTH AMERICAN BREEDING BIRD SURVEY RESULTS AND ANALYSIS, Version 96.3 by J. R. Sauer, J.E. Hines, G. Gough, I. Thomas, B.J. Peterjohn.