| | Brown County | IL | 17009 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=BrownCounty+IL |
| | Carroll County | IL | 17015 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=CarrollCounty+IL |
| | Cass County | IL | 17017 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=CassCounty+IL |
| | Clark County | IL | 17023 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=ClarkCounty+IL |
| | Clay County | IL | 17025 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=ClayCounty+IL |
| | Coles County | IL | 17029 | | Charleston-Mattoon, IL 16660 | | Central | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=ColesCounty+IL |
| | Crawford County | IL | 17033 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=CrawfordCounty+IL |
| | Cumberland County | IL | 17035 | | Effingham, IL 20820 | | Outlying | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=CumberlandCounty+IL |
| | De Witt County | IL | 17039 | | | | | metro county (urban) | nonspecialized | https://maps.google.com/?q=DeWittCounty+IL |
| | Douglas County | IL | 17041 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=DouglasCounty+IL |