Illinois State Route 142 is a north-south highway in Northwestern and South-Central Hamilton. It is the main link between Mc Leansboro, Mt. Vernon, and Eldorado. IL St Rt 142 passes through the following towns in Hamilton County. Dahlgen Delafield Mc Leansboro
Hoodville Dale Broughton IL St Rt 142 is multi-plexed in Hamilton County. Illinois State Route 14, at Mc Leansboro. (SB IL St Rt 142 ONLY) IL St Rt 142 intersects the following highways in Hamilton County. Illinois State Route 242, at Mc Leansboro.