| ZIP Codes: | 21 ZIP Codes (15 Standard, 5 PO Box, 1 Unique) [See All] |
| Area Codes: | 309 / 861 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 2:12:03 PM |
| Population: | 144,279 [See All] |
| FIPS: | 17161 |
| CBSA: | Davenport-Moline-Rock Island, IA-IL |
| Land Area: | 475 sq mi |
| Water Area: | 24 sq mi |
| Coordinates: | 41.4889, -90.5138 |
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144,279 residents live across 21 ZIPs covering 475 sq mi, served by 18 distinct USPS-recognized cities.
Population moved from 148,308 to 144,279 from 2014 to 2024 — a -2.7% change. 5 ZIPs gained residents, 12 lost.
The county's wealthiest ZIP 61240 (Coal Valley, $113,220 median) and poorest ZIP 61239 (Carbon Cliff, $32,177) are 5.0 miles apart — a 3.5× income gap across local geography.
Median home values vary 2.5× across this county — from $99,400 in 61239 (Carbon Cliff) to $245,700 in 61275 (Port Byron).
Density varies 171× across the county — from 12 people/sq mi in 61259 (Illinois City) to 2,073 in 61265 (Moline).
Educational attainment ranges from 4.6% bachelor's+ in 61239 (Carbon Cliff) to 35.5% in 61242 (Cordova) — the breadth of educational profiles across the area.
Within Illinois, this is the #14 most populous of 102 counties and ranks #25 for median household income .
Hosts 1 single-entity Unique ZIP: 61299Rock Island Arsonal .
Weighted by population, the typical household earns about $69,543 across the county — reflecting what a typical resident sees, not a simple ZIP average.
24.8% of adults age 25+ hold a bachelor's degree or higher (24,616 of 99,125 reporting).
15 Standard delivery, 5 PO Box only, 1 single-entity Unique ZIPs serve this county.
Median household income spans 3.5× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 61265 | Moline | Standard | 43,748 | $66,933 | 21.1 | -2.2% |
| 61201 | Rock Island | Standard | 36,766 | $59,396 | 20.7 | -5.7% |
| 61244 | East Moline | Standard | 23,308 | $63,819 | 25.5 | -2.0% |
| 61264 | Milan | Standard | 10,073 | $78,068 | 72.9 | -4.5% |
| 61282 | Silvis | Standard | 8,394 | $64,398 | 4.4 | 7.6% |
| 61240 | Coal Valley | Standard | 5,795 | $113,220 | 39.2 | -7.3% |
| 61275 | Port Byron | Standard | 4,253 | $108,438 | 37.2 | -5.6% |
| 61284 | Taylor Ridge | Standard | 2,599 | $100,505 | 45.9 | 18.8% |
| 61256 | Hampton | Standard | 1,926 | $90,406 | 2.2 | -3.9% |
| 61232 | Andalusia | Standard | 1,469 | $73,971 | 3.5 | -5.7% |
| 61239 | Carbon Cliff | Standard | 1,189 | $32,177 | 1.3 | -0.5% |
| 61242 | Cordova | Standard | 1,135 | $104,219 | 33.9 | 2.5% |
| 61259 | Illinois City | Standard | 1,053 | $91,458 | 86.8 | -10.3% |
| 61279 | Reynolds | Standard | 1,015 | $87,656 | 38.4 | 0.3% |
| 61257 | Hillsdale | Standard | 844 | $64,107 | 41.5 | -21.9% |
| 61278 | Rapids City | PO Box | 678 | $69,938 | 0.0 | 133.0% |
| 61236 | Barstow | PO Box | 34 | $77,813 | 0.1 | -68.8% |
| 61237 | Buffalo Prairie | PO Box | 0 | — | 0.6 | — |
| 61266 | Moline | PO Box | — | — | 0.0 | — |
| 61299 | Rock Island | Unique | — | — | 0.0 | — |
| 61204 | Rock Island | PO Box | — | — | 0.0 | — |