Illinois State Route 173 runs east-west across Northern Boone County. This is the main east-west surface route in this portion of the county. IL St Rt 173 passes through the following towns in Boone County. Capron Poplar Grove
Caledonia
IL St Rt 173 is not multi-plexed in Boone County. IL St Rt 173 intersects the following highway in Boone County. Illinois State Route 76, near Caledonia.
Photo Courtesy: Paul Dienhart A junction marker on NB IL St Rt 76.
