The route begins at the eastern city limit of Montezuma and ends at Iowa 21 east of Deep River.

As it approaches Deep River, the route briefly curves to the north-northeast before turning to the southeast.

It ends one-half mile (0.80 km) east of Deep River at an intersection with Iowa 21.

At the time, it was a short spur route connecting What Cheer to Primary Road No.

This caused the eastern end of Iowa 85 to move east back to the point where it had turned into an east–west route in the 1930s.