South-western Canada (central and eastern British Columbia and south-western Alberta) and western USA in Rocky Mts and Sierra Nevada (Washington to California and east to Wyoming and western Colorado). Winters in west-central and south-central Mexico (south-eastern Sinaloa to east-central Oaxaca).
 
Population
Estimated population is 1,000,000 (2010).
Calliope Hummingbird (Selasphorus calliope) [XC412986]
by Bruce Lagerquist from Kinney Creek drainage,Pocatello, Bannock County, Idaho, United States (song)
Calliope Hummingbird (Selasphorus calliope) [XC132943]
by Richard E. Webster from Silver Creek, Cave Creek Canyon, Cochise County, Arizona, United States (call)
Subspecies
Genus sometimes merged into Mellisuga. Alternatively lumped into Archilochus.
Proposed subspecies lowei (Guerrero) based on a winter specimen, and claimed differences fall within normal variation.