| | Iroquois County | IL | 17075 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=IroquoisCounty+IL |
| | Jasper County | IL | 17079 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=JasperCounty+IL |
| | Jefferson County | IL | 17081 | | Mount Vernon, IL 34500 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=JeffersonCounty+IL |
| | Jo Daviess County | IL | 17085 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=JoDaviessCounty+IL |
| | Johnson County | IL | 17087 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=JohnsonCounty+IL |
| | Knox County | IL | 17095 | | Galesburg, IL 23660 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=KnoxCounty+IL |
| | Lawrence County | IL | 17101 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=LawrenceCounty+IL |
| | McDonough County | IL | 17109 | | Macomb, IL 31380 | | Central | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=McDonoughCounty+IL |
| | Macon County | IL | 17115 | | Decatur, IL 19500 | | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=MaconCounty+IL |
| | Mason County | IL | 17125 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=MasonCounty+IL |