Iowa Highway 175 enters the state by a Missouri River crossing between Decatur, Nebraska and Onawa.

Iowa 175's eastern terminus is at a T intersection with U.S. Highway 63 (US 63) in southwestern Black Hawk County.

Iowa Highway 175 begins at the eastern end of the Burt County Missouri River Bridge west of Onawa.

At Turin, it meets Iowa 37 and turns northeast to follow an alignment which lies next to the Maple River.

It continues northeast from Mapleton through Danbury and Battle Creek and meets US 59 west of Ida Grove.

Iowa Highway 175 then continues east of I-35 by passing through Radcliffe before meeting US 65 in Hubbard.

Iowa Highway 175 was originally designated in 1930 as a very short spur from US 65 to Hubbard but extended west to Stratford by 1937.