Illinois State Route 203 is a north-south highway in Southwestern Madison County. It runs along a old alignment of Illinois State Route 203. IL St Rt 203 passes through the following towns in Madison County. Madison
Granite City
IL St Rt 203 is not multi-plexed in Madison County. IL St Rt 203 intersects the following highways in Madison County. Illinois State Route 162, at Granite City.
