A total of nearly 2,000 acres were listed for sale in LaSalle County, Illinois, recently, representing a total value of $83 million in LaSalle County farms and rural land for sale. LaSalle County ranks fifth in the state for the total number of acres of land currently advertised for sale. Of all farms, rural land, hunting land and other land for sale in LaSalle County, Ottawa featured the most land for sale. LaSalle County is one of the ten largest counties in Illinois (1,148 square miles). It's located in the Northern Illinois region of the state.