Illinois State Route 100 runs north-south in Cass County. It runs along the eastern banks of the Illinois River. IL St Rt 100 passes through the following towns in Cass County. Beardstown
IL St Rt 100 is multi-plexed in Cass County. U.S. Rt. 67, through Cass County.
IL St Rt 100 intersects the following highways in Cass County. Illinois State Route 125, at Beardstown.
NB U.S. Rt. 67/IL St Rt 100 crossing the Illinois River. NB U.S. Rt. 67/IL St Rt 100 crossing the Illinois River. NB U.S. Rt. 67/IL St Rt 100 at the Illinois River. SB U.S. Rt. 67/IL St Rt 100 at 6th in Beardstown. SB U.S. Rt. 67/IL St Rt 100 west of IL St Rt 125. SB U.S. Rt. 67/IL St Rt 100 at IL St Rt 125. A junction marker on WB IL St Rt 125. SB U.S. Rt. 67/IL St Rt 100 south of IL St Rt 125. SB U.S. Rt. 67/IL St Rt 100 south of Beardstown. SB U.S. Rt. 67/IL St Rt 100 near Indiana Creek. NB U.S. Rt. 67/IL St Rt 100 at the Cass/Morgan County Line.
