Its western terminus is at the Indiana state line near Celina, where State Road 67 continues west.

It continues east to St. Marys where it junctions with U.S. Route 33.

In that town, it also crosses State Route 66, State Route 116, and State Route 703, which was its former alignment before a divided highway was built.

After turning south it crosses State Route 219 in New Knoxville and then has an interchange with Interstate 75, continuing into Sidney where it meets State Route 47.

Still going southeast, it briefly joins State Route 235 before turning east and then south again to enter Urbana.