County ZIP codes · Illinois · FIPS 17099
LaSalle County, IL ZIP Codes
LaSalle County, Illinois has 28 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 26 of the residential ones lie mainly in LaSalle County and 2 mainly in a neighboring county; 13 cross the county line. Median household income ranges from $59,060 in 61364 (Streator) to $113,411 in 60552 (Somonauk) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of LaSalle County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $72,530 and $86,786.
They carry 28 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 28 residential ZIP codes in LaSalle County
26 ZIP codes lie mainly in LaSalle County; 2 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 61350 | Ottawa | 23,713 | 155 | $78k | $165k | 100% |
| 61364 | Streator | 17,963 | 114 | $59k | $104k | 78% |
| 61301 | La Salle | 10,398 | 246 | $60k | $129k | 100% |
| 61354 | Peru | 10,290 | 242 | $76k | $159k | 92% |
| 61342 | Mendota | 8,543 | 79 | $65k | $154k | 87% |
| 61341 | Marseilles | 7,692 | 84 | $73k | $201k | 100% |
| 60551 | Sheridan | 5,058 | 85 | $87k | $302k | 100% |
| 61348 | Oglesby | 4,375 | 111 | $76k | $147k | 100% |
| 61360 | Seneca | 3,610 | 76 | $95k | $258k | 79% |
| 60518 | Earlville | 3,289 | 25 | $70k | $166k | 66% |
| 61373 | Utica | 2,123 | 45 | $109k | $237k | 100% |
| 60531 | Leland | 1,885 | 31 | $80k | $229k | 62% |
| 61377 | Wenona | 1,441 | 28 | $57k | $140k | 50% |
| 61370 | Tonica | 1,215 | 27 | $91k | $155k | 100% |
| 61325 | Grand Ridge | 949 | 20 | $88k | $183k | 100% |
| 60549 | Serena | 784 | 33 | $108k | $306k | 100% |
| 61334 | Lostant | 738 | 19 | $86k | $126k | 99% |
| 60537 | Millington | 726 | 879 | $82k | $230k | 68% |
| 61358 | Rutland | 407 | 17 | $88k | $192k | 54% |
| 60470 | Ransom | 358 | 8 | $85k | $131k | 92% |
| 61372 | Troy Grove | 300 | 475 | $84k | $201k | 100% |
| 61316 | Cedar Point | 256 | 199 | $74k | $90k | 100% |
| 61321 | Dana | 224 | 8 | $80k | $92k | 97% |
| 61332 | Leonore | 104 | 140 | $50k | $80k | 100% |
| 61371 | Triumph | 83 | 557 | – | $109k | 100% |
| 60557 | Wedron | no residents | 0 | – | – | 100% |
Partly in LaSalle County
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
14 ZIP codes of LaSalle County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In LaSalle | Elsewhere |
|---|---|---|
| 61364 | 78% | Livingston County 22% |
| 60548 | 34% | DeKalb County 54%; Kendall County 12% |
| 61354 | 92% | Bureau County 8% |
| 61342 | 87% | Bureau County 8%; Lee County 5% |
| 60552 | 19% | DeKalb County 81% |
| 61360 | 79% | Grundy County 21% |
| 60518 | 66% | DeKalb County 25%; Lee County 9% |
| 60531 | 62% | DeKalb County 38% |
| 61377 | 50% | Marshall County 50% |
| 61334 | 99% | |
| 60537 | 68% | Kendall County 32% |
| 61358 | 54% | Marshall County 46% |
| 60470 | 92% | Livingston County 4%; Grundy County 4% |
| 61321 | 97% | Marshall County 3% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
Which first three digits do LaSalle County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. LaSalle County's ZIP codes use 3 prefixes: 604, 605 and 613.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 604 | South Suburban, IL (SCF 604) | 1 | 83 |
| 605 | Fox Valley, IL (SCF 605) | 8 | 65 |
| 613 | Peoria, IL (SCF 615) | 19 | 62 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.