Its southern terminus is at Illinois Route 15 south of Addieville, and its northern terminus is at Illinois Route 140 east of Alhambra.

[1] Illinois 160 runs northwest from Addieville to New Memphis via Okawville (near Interstate 64) before turning north.

Illinois 160 passes through the town of Grantfork just north of Interstate 70.

SBI Route 160 originally ran from Alton to Greenville.

[3] In 1959 it was used on the current Illinois 160 from New Baden to Highland; in 1960, it was extended south to New Memphis.