| | | Rock Island County | IL | 17161 | | Davenport-Moline-Rock
Island, IA-IL 19340 | Davenport-Moline, IA-IL 209 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=RockIslandCounty+IL |
| | | Saline County | IL | 17165 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=SalineCounty+IL |
| | | Sangamon County | IL | 17167 | | Springfield, IL 44100 | Springfield-Jacksonville-Lincoln,
IL 522 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=SangamonCounty+IL |
| | | Schuyler County | IL | 17169 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=SchuylerCounty+IL |
| | | Scott County | IL | 17171 | | Jacksonville, IL 27300 | Springfield-Jacksonville-Lincoln,
IL 522 | Outlying | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=ScottCounty+IL |
| | | Shelby County | IL | 17173 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=ShelbyCounty+IL |
| | | St. Clair County | IL | 17163 | | St. Louis, MO-IL 41180 | St. Louis-St.
Charles-Farmington, MO-IL 476 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=St.ClairCounty+IL |
| | | Stark County | IL | 17175 | | Peoria, IL 37900 | Peoria-Canton, IL 427 | Outlying | metro county (urban) | farm-dependent | https://maps.google.com/?q=StarkCounty+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 |
| | | Tazewell County | IL | 17179 | | Peoria, IL 37900 | Peoria-Canton, IL 427 | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=TazewellCounty+IL |
