| | Boone County | IL | 17007 | | Rockford, IL 40420 | Rockford-Freeport-Rochelle,
IL 466 | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=BooneCounty+IL |
| | Ogle County | IL | 17141 | | Rochelle, IL 40300 | Rockford-Freeport-Rochelle,
IL 466 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=OgleCounty+IL |
| | Stephenson County | IL | 17177 | | Freeport, IL 23300 | Rockford-Freeport-Rochelle,
IL 466 | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=StephensonCounty+IL |
| | Winnebago County | IL | 17201 | | Rockford, IL 40420 | Rockford-Freeport-Rochelle,
IL 466 | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=WinnebagoCounty+IL |