Illinois State Route 15 is the only east-west highway in Wabash County. This is the eastern most county that this highway passes through in Illinois. It also has the only bridge into Indiana from Wabash County, Illinois. IL St Rt 15 passes through the following town in Wabash County. Mt. Carmel
A junction marker on NB IL St Rt 1/WB IL St Rt 1. WB IL St Rt 15 at the Illinois/Indiana State Line. A Wabash County mile marker. The eastern end of IL St Rt 15. The eastern end marker.
