| | Marion County | OH | 39101 | | Marion, OH 32020 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=MarionCounty+OH |
| | Morrow County | OH | 39117 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=MorrowCounty+OH |
| | Muskingum County | OH | 39119 | | Zanesville, OH 49780 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=MuskingumCounty+OH |
| | Perry County | OH | 39127 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=PerryCounty+OH |
| | Pickaway County | OH | 39129 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=PickawayCounty+OH |
| | Ross County | OH | 39141 | | Chillicothe, OH 17060 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=RossCounty+OH |
| | Union County | OH | 39159 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=UnionCounty+OH |
| | Champaign County | OH | 39021 | | Urbana, OH 46500 | Dayton-Springfield-Kettering,
OH 212 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=ChampaignCounty+OH |
| | Clark County | OH | 39023 | | Springfield, OH 44220 | Dayton-Springfield-Kettering,
OH 212 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=ClarkCounty+OH |
| | Darke County | OH | 39037 | | Greenville, OH 24820 | Dayton-Springfield-Kettering,
OH 212 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=DarkeCounty+OH |