Boone County is a county located in the U.S. state of Illinois. As of the most recent data available, the county has a population of approximately 41,786 people, with a population density of about 148.70 persons per square mile.
The county spans a total land area of 281.00 square miles (728.00 square kilometers). The administrative center and county seat is Belvidere, which often serves as a hub for local governance and services. The largest city within the county by population is Belvidere.
Geographically, Boone County experiences varied elevations, with its highest point at Capron 910 ft and its lowest point at Poplar Grove 0 ft. The region operates in the UTC-6.