The Bay Region of PBMA consists of the following 12 California Counties: 

County Population
Alameda   County 1,647,704
Contra   Costa County 1,135,127
Marin   County 260,651
Monterey   County 435,232
Napa   County 142,166
San   Benito County 59,414
San Francisco County 870,887
San   Mateo County 764,797
Santa   Clara County 1,919,402
Santa   Cruz County 274,673
Solano   County 440,207
Sonoma   County 503,070