Ogle County is a county in Illinois, United States, along the Rock River in the north-central part of the state. It had a population of 51,788 at the 2020 census and covers 759 square miles (1,970 km2) centred near 42°02′N 89°19′W.
Oregon is the county seat, and its postal code is 61061. The county holds four cities, nine villages and several unincorporated communities, spread across 24 townships. Ogle County sits in the Central time zone.
Towns & Villages in Ogle County
Ogle County’s largest places are its cities along the Rock River and rail lines; smaller villages and unincorporated crossroads communities fill out the townships between them. CDP = Census-Designated Place (unincorporated, no local government); Unincorp. = an unincorporated community with no census boundary.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Oregon | City · seat | Oregon-Nashua | 3,604 | 61061 |
| Rochelle | City | Flagg | 9,446 | 61068 |
| Byron | City | Byron | 3,784 | 61010 |
| Polo | City | Buffalo | 2,291 | 61064 |
| Mount Morris | Village | Mount Morris | — | 61054 |
| Stillman Valley | Village | Marion | — | 61084 |
| Forreston | Village | Forreston | — | 61030 |
| Davis Junction | Village | Flagg | — | 61020 |
| Leaf River | Village | Leaf River | — | 61047 |
| Monroe Center | Village | Monroe | — | 61052 |
| Adeline | Village | Marion | — | 61068 |
| Creston | Village | Dement | — | 60113 |
| Hillcrest | Village | Scott | — | — |
| Grand Detour | CDP | Grand Detour | — | — |
| Baileyville | CDP | White Rock | — | 61007 |
| Holcomb | CDP | Rockvale | — | 61043 |
| Kings | CDP | Rockvale | — | — |
| Lost Nation | CDP | Pine Rock | — | — |
| Chana | Unincorp. | Buffalo | — | 61015 |
| Lindenwood | Unincorp. | Lynnville | — | 61049 |
| Woosung | Unincorp. | Woosung | — | 61091 |
| White Rock | Unincorp. | White Rock | — | — |
| Egan | Unincorp. | Pine Creek | — | — |
| Daysville | Unincorp. | Oregon-Nashua | — | — |
A handful of names on older lists are subdivisions or mobile-home parks rather than historic communities (for example Briarwood, Byron Hills Estates, Crestwood Acres, Frahms Country Acres, Highland Estates, Prairieview Estates, Ramsey Acres, Rolling Greens MH Park, Skare Estates, Von Glen Acres and Woodland Acres) — real addresses, but not distinct settlements, so they are left out of the table above. A few entries on the old page were not Ogle County places at all: Buffalo Grove and Carthage are unrelated Illinois place names elsewhere in the state, and Maryland and Pennsylvania Corners are township names, not towns.
Townships
Ogle County’s 24 civil townships each elect their own township officials and maintain local roads outside city limits.
| Township | Main settlements |
|---|---|
| Flagg | Rochelle, Davis Junction |
| Byron | Byron |
| Oregon-Nashua | Oregon, Daysville |
| Buffalo | Polo, Chana |
| Mount Morris | Mount Morris |
| Marion | Stillman Valley, Adeline |
| Forreston | Forreston |
| Rockvale | Holcomb, Kings |
| Scott | Hillcrest |
| Leaf River | Leaf River |
| Monroe | Monroe Center |
| Dement | Creston |
| White Rock | Baileyville, White Rock |
| Grand Detour | Grand Detour |
| Pine Rock | Lost Nation |
| Woosung | Woosung |
| Lynnville | Lindenwood |
| Pine Creek | Egan |
| Brookville | rural |
| Eagle Point | rural |
| LaFayette | rural |
| Lincoln | rural |
| Taylor | rural |
| Maryland | rural |
ZIP Codes
- 61061 — Oregon
- 61068 — Rochelle (also serves Adeline)
- 61010 — Byron
- 61064 — Polo
- 61054 — Mount Morris
- 61084 — Stillman Valley
- 61030 — Forreston
- 61020 — Davis Junction
- 61047 — Leaf River
- 61052 — Monroe Center
- 61015 — Chana
- 61049 — Lindenwood
- 61007 — Baileyville
- 61043 — Holcomb (PO Box only)
- 61091 — Woosung (PO Box only)
- 60113 — Creston (PO Box only)
Hillcrest, Grand Detour, Kings, Lost Nation and White Rock have no ZIP code of their own and use a neighboring town’s mail service.
Geography
Ogle County straddles the Rock River valley, with rolling farmland to the east and the river’s wooded bluffs cutting through the west-central townships near Oregon and Grand Detour. Most of the county drains toward the Rock River, a tributary of the Mississippi. It borders Winnebago County to the north, Boone County to the northeast, Stephenson County to the northwest, DeKalb County to the east, Carroll County to the west, Lee County to the south, and Whiteside County to the southwest.
Demographics
Ogle County had 51,788 residents at the 2020 census, spread across about 68 people per square mile. Rochelle (9,446) and Byron (3,784) are the county’s two largest communities, together holding a quarter of the county’s population. Median household income in Ogle County runs below the Illinois median of $80,306, typical for a mostly rural Rock River Valley county outside the Chicago metro.
Economy & Local Life
Agriculture — corn and soybeans on the county’s flatter eastern townships — remains a major employer, alongside manufacturing and distribution clustered around Rochelle’s rail-served industrial park (Union Pacific and BNSF both cross the city) and the Byron Generating Station, a nuclear plant on the Rock River that is one of the county’s largest single employers and taxpayers. Oregon, the seat, is known regionally for its riverfront parks and the Lorado Taft-associated art colony history along the Rock River bluffs.
History
Ogle County was organized on January 16, 1836, carved from Jo Daviess and LaSalle counties, and named for Captain Joseph Ogle, a Revolutionary War veteran who had settled in Illinois in 1785. Early settlement concentrated along the Rock River at Oregon and Grand Detour, where John Deere developed his self-scouring steel plow in the 1830s before relocating his works to Moline. The Black Hawk War of 1832 passed through the surrounding region just before the county’s formal organization.
Getting There
Illinois Route 2 follows the Rock River through Oregon and Byron, U.S. Route 51 runs north–south along the county’s eastern edge through Rochelle, and Interstate 39 crosses the county connecting Rochelle to Rockford. Approximate distances:
- Rockford — 20 miles north
- Dixon — 15 miles south
- DeKalb — 25 miles east
- Freeport — 25 miles northwest
Chicago Rockford International Airport, about 20 miles north in Winnebago County, is the nearest commercial airport.
Frequently Asked Questions
Where is Ogle County, Illinois?
It sits in north-central Illinois along the Rock River, between Rockford and Dixon.
What is the population of Ogle County?
51,788 residents at the 2020 census.
How big is Ogle County?
759 square miles (1,970 km2) of land and water.
What is the county seat of Ogle County?
Oregon is the county seat.
How many towns and villages are in Ogle County?
Four cities, nine villages and several unincorporated communities across 24 townships.
What ZIP codes are in Ogle County?
Sixteen ZIP codes serve the county, led by 61061 (Oregon), 61068 (Rochelle), 61010 (Byron) and 61064 (Polo).
What is Ogle County known for?
The Rock River bluffs at Oregon and Grand Detour, where John Deere built his first self-scouring plow, and the Byron nuclear generating station.
More counties in this state: Towns and villages in Illinois.