Illinois State Route 142 is a east-west highway in Southeastern Jefferson County. It runs from Mt. Vernon to the Jefferson/Hamilton County Line. IL St Rt 142 passes through the following towns in Mt. Vernon. Belle Rive Opdyke Mt. Vernon
IL St Rt 142 is not multi-plexed in Jefferson County. IL St Rt 142 crosses the following highways in Jefferson County. Illinois State Route 37, at Mt. Vernon. Illinois State Route 148, at Mt. Vernon. Interstate 64, near Mt. Vernon. (NO INTERCHANGE)
A junction marker on NB IL St Rt 37. A Jefferson County mile marker. The northern end marker.
