| ZIP Codes: | 16 ZIP Codes (13 Standard, 3 PO Box, 0 Unique) [See All] |
| Area Codes: | 779 / 815 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 2:12:02 PM |
| Population: | 50,102 [See All] |
| FIPS: | 17141 |
| CBSA: | Rochelle, IL |
| Land Area: | 720 sq mi |
| Water Area: | 3 sq mi |
| Coordinates: | 42.0540, -89.2688 |
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50,102 residents live across 16 ZIPs covering 720 sq mi, served by 16 distinct USPS-recognized cities.
Population moved from 51,106 to 50,102 from 2014 to 2024 — a -2.0% change. 8 ZIPs gained residents, 8 lost.
The county's wealthiest ZIP 61020 (Davis Junction, $105,769 median) and poorest ZIP 61054 (Mount Morris, $47,467) are 19.4 miles apart — a 2.2× income gap across local geography.
Median home values vary 2.0× across this county — from $121,400 in 61054 (Mount Morris) to $242,200 in 61047 (Leaf River).
Density varies 2995× across the county — from 22 people/sq mi in 61015 (Chana) to 65,106 in 60113 (Creston).
Educational attainment ranges from 16.9% bachelor's+ in 61054 (Mount Morris) to 35.5% in 61084 (Stillman Valley) — the breadth of educational profiles across the area.
Within Illinois, this is the #28 most populous of 102 counties and ranks #21 for median household income .
Weighted by population, the typical household earns about $81,937 across the county — reflecting what a typical resident sees, not a simple ZIP average.
23.9% of adults age 25+ hold a bachelor's degree or higher (8,364 of 34,964 reporting).
13 Standard delivery, 3 PO Box only, 0 single-entity Unique ZIPs serve this county.
A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 61068 | Rochelle | Standard | 14,788 | $73,214 | 115.8 | -0.9% |
| 61010 | Byron | Standard | 7,497 | $93,613 | 39.7 | -9.3% |
| 61061 | Oregon | Standard | 6,766 | $87,829 | 109.8 | 1.8% |
| 61064 | Polo | Standard | 3,757 | $75,386 | 108.3 | 6.2% |
| 61054 | Mount Morris | Standard | 3,610 | $47,467 | 37.9 | -9.6% |
| 61084 | Stillman Valley | Standard | 3,201 | $102,817 | 35.0 | 9.8% |
| 61020 | Davis Junction | Standard | 3,149 | $105,769 | 31.2 | -4.6% |
| 61030 | Forreston | Standard | 2,194 | $71,655 | 62.4 | -11.2% |
| 61047 | Leaf River | Standard | 1,622 | $86,056 | 66.2 | -2.3% |
| 61052 | Monroe Center | Standard | 1,145 | $91,797 | 27.6 | 12.9% |
| 61015 | Chana | Standard | 901 | $97,500 | 41.4 | 33.1% |
| 61049 | Lindenwood | Standard | 579 | $91,607 | 18.4 | 8.0% |
| 60113 | Creston | PO Box | 306 | $67,396 | 0.0 | -15.7% |
| 61091 | Woosung | PO Box | 248 | — | 0.8 | 202.4% |
| 61007 | Baileyville | Standard | 196 | — | 25.4 | -69.2% |
| 61043 | Holcomb | PO Box | 143 | $69,063 | 0.5 | 64.4% |