Breeds patchily in south-western USA (from southern Nevada and southern Utah south to southern California, east to extreme western Texas) and extreme northern Mexico (northern Chihuahua). Migrates to coastal regions of western Mexico, mainly from southern Sonora south to western Guerrero.
 
Population
Estimated population is 1,200,000 (2010).
Lucy's Warbler (Leiothlypis luciae) [XC616475]
by Richard E. Webster from Grand Canyon Village, Coconino County, Arizona, United States (song)
Lucy's Warbler (Leiothlypis luciae) [XC557812]
by Richard E. Webster from Farm Units, Cibola National Wildlife Refuge, La Paz County, Arizona, United States (call, song)