THE LASALLE COUNTY LAND BRIEF
Land in the
Illinois/Indiana Prairies setting.
LaSalle County has 1,135.1 square miles of land in Illinois. The mapped landscape region in LaSalle County is Illinois/Indiana Prairies.
Glaciated plains historically supported tallgrass prairie mixed with oak and hickory woodland. Dark prairie soils and broad farming landscapes distinguish much of the Central Corn Belt.
Regional context: Central Corn Belt Plains ↗ · Regional mapping across the county footprint
Finding your parcel within LaSalle County
The atlas lists 70 cities, towns, townships, and Census communities associated with LaSalle County, including Brookfield, Osage, Earl. The list includes overlapping geography types and does not divide the county into exclusive service areas.
LaSalle County by land and water
The Census records 13.1 square miles of water within LaSalle County, or 1.1% of its total area. That share is close to LaSalle County’s 1.1%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, LaSalle County has 74.8 times the land area of nearby Ottawa township (15.2 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Bureau County, DeKalb County, Grundy County, Kendall County, Lee County, Livingston County, Marshall County, Putnam County and other counties within Illinois. A tract near one of these lines should be matched to the county identifier on its own records.

