| | Delaware County | OH | 39041 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=DelawareCounty+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 |
| | Guernsey County | OH | 39059 | | Cambridge, OH 15740 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=GuernseyCounty+OH |
| | Hocking County | OH | 39073 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | recreation | https://maps.google.com/?q=HockingCounty+OH |
| | Knox County | OH | 39083 | | Mount Vernon, OH 34540 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=KnoxCounty+OH |
| | Licking County | OH | 39089 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=LickingCounty+OH |
| | Logan County | OH | 39091 | | Bellefontaine, OH 13340 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=LoganCounty+OH |
| | Madison County | OH | 39097 | | Columbus, OH 18140 | Columbus-Marion-Zanesville,
OH 198 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=MadisonCounty+OH |