| | Bell County | KY | 21013 | | Middlesborough, KY 33180 | Middlesborough-Corbin, KY 371 | Central | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=BellCounty+KY |
| | Clay County | KY | 21051 | | Corbin, KY 18340 | Middlesborough-Corbin, KY 371 | Outlying | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=ClayCounty+KY |
| | Knox County | KY | 21121 | | Corbin, KY 18340 | Middlesborough-Corbin, KY 371 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=KnoxCounty+Kentucky |
| | Laurel County | KY | 21125 | | Corbin, KY 18340 | Middlesborough-Corbin, KY 371 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=LaurelCounty+Kentucky |
| | Whitley County | KY | 21235 | | Corbin, KY 18340 | Middlesborough-Corbin, KY 371 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=WhitleyCounty+Kentucky |