| | Ogle County | IL | 17141 | | Rochelle, IL 40300 | Rockford-Freeport-Rochelle,
IL 466 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=OgleCounty+IL |
| | Peoria County | IL | 17143 | | Peoria, IL 37900 | Peoria-Canton, IL 427 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=PeoriaCounty+IL |
| | Perry County | IL | 17145 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=PerryCounty+IL |
| | Piatt County | IL | 17147 | | Champaign-Urbana, IL 16580 | Champaign-Urbana-Denville,
IL 169 | Outlying | metro county (urban) | farm-dependent | https://maps.google.com/?q=PiattCounty+IL |
| | Pike County | IL | 17149 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=PikeCounty+IL |
| | Pope County | IL | 17151 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=PopeCounty+IL |
| | Pulaski County | IL | 17153 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=PulaskiCounty+IL |
| | Putnam County | IL | 17155 | | Ottawa, IL 36837 | Chicago-Naperville,
IL-IN-WI 176 | Outlying | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=PutnamCounty+Illinois |
| | Randolph County | IL | 17157 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=RandolphCounty+IL |
| | Richland County | IL | 17159 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=RichlandCounty+IL |