Illinois Route 150 runs in southwestern Illinois, in Randolph and Perry Counties. It connects to Missouri Route 51 by crossing the Mississippi River at Chester, then runs northeasterly to end at Illinois 154 north of Cutler.
Illinois 150 begins crossing the Mississippi River into Chester, Illinois, from Missouri Route 51:
After zigzagging through parts of Chester, Illinois 3 joins from the south as Illinois 150 heads northeasterly:
After a short concurrency, Illinois 3 continues toward the north as Illinois 150 continues northeasterly:
Illinois 150 curves to head directly eastward as Illinois 4 joins it from the north:
After passing through Steeleville and Percy, Illinois 4 splits off of Illinois 150 to continue southward:
Illinois 150 curves to face northerly and ends at Illinois 154 north of Cutler.