| | Mercer County | OH | 39107 | | Celina, OH 16380 | Lima-Van Wert-Celina, OH 338 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=MercerCounty+OH |
| | Montgomery County | OH | 39113 | | Dayton-Kettering-Beavercreek,
OH 19430 | Dayton-Springfield-Kettering,
OH 212 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=MontgomeryCounty+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 |
| | Ottawa County | OH | 39123 | | Sandusky, OH 41780 | Cleveland-Akron-Canton,
OH 184 | Central | nonmetro county (rural) | recreation | https://maps.google.com/?q=OttawaCounty+Ohio |
| | Portage County | OH | 39133 | | Akron, OH 10420 | Cleveland-Akron-Canton,
OH 184 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=PortageCounty+OH |
| | Richland County | OH | 39139 | | Mansfield, OH 31900 | Mansfield-Ashland-Bucyrus,
OH 360 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=RichlandCounty+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 |
| | Sandusky County | OH | 39143 | | Fremont, OH 23380 | Cleveland-Akron-Canton,
OH 184 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=SanduskyCounty+OH |
| | Scioto County | OH | 39145 | | Portsmouth, OH 39020 | Charleston-Huntington-Ashland,
WV-OH-KY 170 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=SciotoCounty+OH |
| | Seneca County | OH | 39147 | | Tiffin, OH 45660 | Findlay-Tiffin, OH 248 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=SenecaCounty+OH |