LaSalle County is the second largest county (by area) in Illinois. According to the 2017 Census of Agriculture, there were 1,496 farms in LaSalle County, spanning 573,041 acres, with an average farm size of 383 acres. The population of LaSalle County was 6,006 (based on 2010 census). Four state parks (Buffalo Rock, Illini, Matthiessen, and Starved Rock) are located in LaSalle County, most along the Illinois River. Ottawa is LaSalle County’s largest city and the county seat. LaSalle County’s temperatures range from 12°F during January to 85°F during July. Average monthly precipitation ranges from 1.32" during February to 4.13" during August. If you're looking for land for sale in LaSalle County, IL, check out Land Pro LLC's current listings below. If there are no current listings in LaSalle County, take a look at land for sale in neighboring Bureau County, DeKalb County, Grundy County, Kendall County, Lee County, Livingston County, Marshall County, Putnam County, and Woodford County. You can also view all the Illinois land offered for sale by Land Pro LLC.