| | | Napa County | CA | 06055 | | Napa, CA 34900 | San Jose-San
Francisco-Oakland, CA 488 | Central | metro county (urban) | recreation | https://maps.google.com/?q=NapaCounty+CA |
| | | Monterey County | CA | 06053 | | Salinas, CA 41500 | | Central | metro county (urban) | recreation | https://maps.google.com/?q=MontereyCounty+CA |
| | | Mono County | CA | 06051 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=MonoCounty+CA |
| | | Modoc County | CA | 06049 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=ModocCounty+CA |
| | | Merced County | CA | 06047 | | Merced, CA 32900 | San Jose-San
Francisco-Oakland, CA 488 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=MercedCounty+California |
| | | Mendocino County | CA | 06045 | | Ukiah, CA 46380 | | Central | nonmetro county (rural) | recreation | https://maps.google.com/?q=MendocinoCounty+CA |
| | | Mariposa County | CA | 06043 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=MariposaCounty+CA |
| | | Marin County | CA | 06041 | San Rafael, CA 42034 | San
Francisco-Oakland-Fremont,
CA 41860 | San Jose-San
Francisco-Oakland, CA 488 | Central | metro county (urban) | recreation | https://maps.google.com/?q=MarinCounty+CA |
| | | Madera County | CA | 06039 | | Fresno, CA 23420 | Fresno-Hanford-Corcoran,
CA 260 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=MaderaCounty+California |
| | | Los Angeles County | CA | 06037 | Los Angeles-Long
Beach-Glendale, CA 31084 | Los Angeles-Long
Beach-Anaheim, CA 31080 | Los Angeles-Long Beach,
CA 348 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=LosAngelesCounty+CA |
