| | Reynolds County | MO | 29179 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=ReynoldsCounty+MO |
| | Ripley County | MO | 29181 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=RipleyCounty+MO |
| | St. Clair County | MO | 29185 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=St.ClairCounty+MO |
| | Ste. Genevieve County | MO | 29186 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=Ste.GenevieveCounty+MO |
| | St. Francois County | MO | 29187 | | Farmington, MO 22100 | St. Louis-St.
Charles-Farmington, MO-IL 476 | Central | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=St.FrancoisCounty+MO |
| | Saline County | MO | 29195 | | Marshall, MO 32180 | | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=SalineCounty+MO |
| | Schuyler County | MO | 29197 | | Kirksville, MO 28860 | | Outlying | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=SchuylerCounty+MO |
| | Scotland County | MO | 29199 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=ScotlandCounty+MO |
| | Scott County | MO | 29201 | | Sikeston, MO 43460 | Cape Girardeau-Sikeston,
MO-IL 164 | Central | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=ScottCounty+MO |
| | Shannon County | MO | 29203 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=ShannonCounty+MO |