| | Davis County | IA | 19051 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=DavisCounty+IA |
| | Decatur County | IA | 19053 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=DecaturCounty+IA |
| | Delaware County | IA | 19055 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=DelawareCounty+IA |
| | Dubuque County | IA | 19061 | | Dubuque, IA 20220 | | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=DubuqueCounty+IA |
| | Emmet County | IA | 19063 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=EmmetCounty+IA |
| | Fayette County | IA | 19065 | | | | | nonmetro county (rural) | nonspecialized | https://maps.google.com/?q=FayetteCounty+IA |
| | Floyd County | IA | 19067 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=FloydCounty+IA |
| | Franklin County | IA | 19069 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=FranklinCounty+IA |
| | Fremont County | IA | 19071 | | | | | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=FremontCounty+IA |
| | Greene County | IA | 19073 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=GreeneCounty+IA |