| | Mineral County | MT | 30061 | | Missoula, MT 33540 | | Outlying | nonmetro county (rural) | recreation | https://maps.google.com/?q=MineralCounty+MT |
| | Missoula County | MT | 30063 | | Missoula, MT 33540 | | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=MissoulaCounty+MT |
| | Musselshell County | MT | 30065 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=MusselshellCounty+MT |
| | Park County | MT | 30067 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=ParkCounty+MT |
| | Petroleum County | MT | 30069 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=PetroleumCounty+MT |
| | Phillips County | MT | 30071 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=PhillipsCounty+MT |
| | Pondera County | MT | 30073 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=PonderaCounty+MT |
| | Powder River County | MT | 30075 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=PowderRiverCounty+MT |
| | Powell County | MT | 30077 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=PowellCounty+MT |
| | Prairie County | MT | 30079 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=PrairieCounty+MT |