| | Delaware County | OH | 39041 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=DelawareCounty+OH |
| | Erie County | OH | 39043 | | Sandusky, OH 41780 | Cleveland-Akron-Canton,
OH 184 | Central | nonmetro county (rural) | recreation | https://maps.google.com/?q=ErieCounty+OH |
| | Fairfield County | OH | 39045 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=FairfieldCounty+OH |
| | Fayette County | OH | 39047 | | Washington Court House,
OH 47920 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=FayetteCounty+OH |
| | Franklin County | OH | 39049 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=FranklinCounty+OH |
| | Fulton County | OH | 39051 | | Toledo, OH 45780 | | Outlying | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=FultonCounty+Ohio |
| | Gallia County | OH | 39053 | | Gallipolis, OH 23680 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=GalliaCounty+Ohio |
| | Geauga County | OH | 39055 | | Cleveland, OH 17410 | Cleveland-Akron-Canton,
OH 184 | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=GeaugaCounty+OH |
| | Greene County | OH | 39057 | | Dayton-Kettering-Beavercreek,
OH 19430 | Dayton-Springfield-Kettering,
OH 212 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=GreeneCounty+OH |
| | Guernsey County | OH | 39059 | | Cambridge, OH 15740 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=GuernseyCounty+OH |