| | Mono County | CA | 06051 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=MonoCounty+CA |
| | Nevada County | CA | 06057 | | Truckee-Grass Valley, CA 46020 | Sacramento-Roseville, CA 472 | Central | nonmetro county (rural) | recreation | https://maps.google.com/?q=NevadaCounty+CA |
| | Plumas County | CA | 06063 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=PlumasCounty+CA |
| | Sierra County | CA | 06091 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=SierraCounty+CA |
| | Siskiyou County | CA | 06093 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=SiskiyouCounty+CA |
| | Tehama County | CA | 06103 | | Red Bluff, CA 39780 | Redding-Red Bluff, CA 454 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=TehamaCounty+CA |
| | Trinity County | CA | 06105 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=TrinityCounty+CA |
| | Tuolumne County | CA | 06109 | | Sonora, CA 43760 | | Central | nonmetro county (rural) | recreation | https://maps.google.com/?q=TuolumneCounty+CA |