| | | Madison County | IA | 19121 | | Des Moines-West Des
Moines, IA 19780 | Des Moines-West Des
Moines-Ames, IA 218 | Outlying | in metro of > 250k
< 1m | nonspecialized | https://maps.google.com/?q=MadisonCounty+IA |
| | | Mahaska County | IA | 19123 | | Oskaloosa, IA 36820 | Des Moines-West Des
Moines-Ames, IA 218 | Central | not in metro; pop > 5K
< 20k;
non-metro-adjacent | nonspecialized | https://maps.google.com/?q=MahaskaCounty+IA |
| | | Marion County | IA | 19125 | | Pella, IA 37800 | Des Moines-West Des
Moines-Ames, IA 218 | Central | not in metro; pop > 5k
< 20k; metro-adjacent | manufacturing-dependent | https://maps.google.com/?q=MarionCounty+IA |
| | | Marshall County | IA | 19127 | | Marshalltown, IA 32260 | | Central | not in metro; pop
>20k; metro-adjacent | manufacturing-dependent | https://maps.google.com/?q=MarshallCounty+IA |
| | | Mills County | IA | 19129 | | Omaha, NE-IA 36540 | Omaha-Fremont, NE-IA 420 | Outlying | in metro of > 250k
< 1m | federal/state
government-dependent | https://maps.google.com/?q=MillsCounty+IA |
| | | Mitchell County | IA | 19131 | | | | | not in metro; pop <
5k; non-metro-adjacent | manufacturing-dependent | https://maps.google.com/?q=MitchellCounty+IA |
| | | Monona County | IA | 19133 | | | | | not in metro; pop <
5k; metro-adjacent | farm-dependent | https://maps.google.com/?q=MononaCounty+IA |
| | | Monroe County | IA | 19135 | | | | | not in metro; pop <
5k; non-metro-adjacent | manufacturing-dependent | https://maps.google.com/?q=MonroeCounty+IA |
| | | Montgomery County | IA | 19137 | | | | | not in metro; pop > 5k
< 20k; metro-adjacent | nonspecialized | https://maps.google.com/?q=MontgomeryCounty+IA |
| | | Muscatine County | IA | 19139 | | Muscatine, IA 34700 | Davenport-Moline, IA-IL 209 | Central | not in metro; pop
>20k; metro-adjacent | manufacturing-dependent | https://maps.google.com/?q=MuscatineCounty+IA |
