| | Loving County | TX | 48301 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=LovingCounty+TX |
| | McCulloch County | TX | 48307 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=McCullochCounty+TX |
| | McMullen County | TX | 48311 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=McMullenCounty+TX |
| | Madison County | TX | 48313 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=MadisonCounty+TX |
| | Marion County | TX | 48315 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=MarionCounty+TX |
| | Mason County | TX | 48319 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=MasonCounty+TX |
| | Menard County | TX | 48327 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=MenardCounty+TX |
| | Milam County | TX | 48331 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=MilamCounty+TX |
| | Mills County | TX | 48333 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=MillsCounty+TX |
| | Mitchell County | TX | 48335 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=MitchellCounty+TX |