South-western Canada (southern British Columbia and extreme south-western Alberta) and western USA south to extreme north-western Mexico (northern Baja California). Winters south to central Mexico (Coahuila south to Michoacán).
 
Population
Estimated population is 1,900,000 (2010) and decreasing.
Cassin's Finch (Haemorhous cassinii) [XC563639]
by Peter Ward and Ken Hall from Idlewild Campground, United States (song)
Cassin's Finch (Haemorhous cassinii) [XC598465]
by Richard E. Webster from Okanagan-Similkameen A (near Osoyoos), Okanagan-Similkameen, British Columbia, Canada (?)