| | | Clark County | OH | 39023 | | Springfield, OH 44220 | Dayton-Springfield-Kettering,
OH 212 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=ClarkCounty+OH |
| | | Clermont County | OH | 39025 | | Cincinnati, OH-KY-IN 17140 | Cincinnati-Wilmington,
OH-KY-IN 178 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=ClermontCounty+OH |
| | | Clinton County | OH | 39027 | | Wilmington, OH 48940 | Cincinnati-Wilmington,
OH-KY-IN 178 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=ClintonCounty+OH |
| | | Columbiana County | OH | 39029 | | Salem, OH 41400 | Youngstown-Warren-Salem,
OH 566 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=ColumbianaCounty+OH |
| | | Cuyahoga County | OH | 39035 | | Cleveland, OH 17410 | Cleveland-Akron-Canton,
OH 184 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=CuyahogaCounty+OH |
| | | 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 |
| | | Gallia County | OH | 39053 | | Gallipolis, OH 23680 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=GalliaCounty+Ohio |
| | | Guernsey County | OH | 39059 | | Cambridge, OH 15740 | Columbus-Marion-Zanesville,
OH 198 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=GuernseyCounty+OH |
