Illinois State Route 100 runs breifly in Western Morgan County. Most of this highway runs along U.S. Rt. 67. It runs along the eastern bluffs of the Illinois River Valley. IL St Rt 100 does not pass through any towns in Morgan County. IL St Rt 100 is multi-plexed in Morgan County. U.S. Rt. 67, from the Cass/Morgan County Line to near Meredosia.
SB U.S. Rt. 67/IL St Rt 100 at the Cass/Morgan County Line. SB U.S. Rt. 67/IL St Rt 100 at the Cass/Morgan County Line. SB U.S. Rt. 67/IL St Rt 100 near Arenzville Road. SB U.S. Rt. 67/IL St Rt 100 north of IL St Rt 104. A junction marker on EB IL St Rt 104. SB U.S. Rt. 67/IL St Rt 100; EB IL St Rt 104 near Meredosia. SB U.S. Rt. 67/IL St Rt 100; EB IL St Rt 104 south of west IL St Rt 104. SB U.S. Rt. 67/IL St Rt 100; EB IL St Rt 104 near Meredosia. A junction marker on SB U.S. Rt. 67/IL St Rt 100; EB IL St Rt 104. SB IL St Rt 100 south of U.S. Rt. 67/IL St Rt 104. A junction marker on NB IL St Rt 100. SB IL St Rt 100 near the Scott/Morgan County Line. NB IL St Rt 100 at the Scot/Morgan County Line.
