The two crossword solutions for the term 'Illinois River City' are Peoria (6 letters) and LaSalle (7 letters). Peoria is a city in central Illinois, located on the Illinois River. It is the largest city on the Illinois River and the county seat of Peoria County. LaSalle is a city in LaSalle County, Illinois, located on the Illinois River. It is the county seat of LaSalle County and is part of the Ottawa-Peru, IL Micropolitan Statistical Area. Both cities are important hubs for transportation, industry, and commerce in the region.