Illinois State Route 76 runs north-south in the center of Boone County. This runs from the Illinois/Wisconsin State Line to Belvidere. IL St Rt 76 passes through the following town in Boone County. Belvidere IL St Rt 76 is not multi-plexed in Boone County. IL St Rt 76 intersects the following highways in Boone County. Wisconsin State Route 140, at the Wisconsin/Illinois State Line. Illinois State Route 173, near Poplar Grove.
