Iowa Highway 175 begins at the eastern end of the Burt County Missouri River Bridge west of Onawa. At Onawa, it intersects Interstate 29. At Turin, it meets Iowa 37 and turns northeast to follow an alignment which lies next to the Maple River. It continues through Castana and meets Iowa 141 in Mapleton. At Mapleton, Iowa 175 overlaps Iowa 141 through town. This is a wrong-way concurrency, with eastbound Iowa 175 and westbound Iowa 141 routed on one side of the road, and vice versa. It continues northeast from Mapleton through Danbury and Battle Creek and meets US 59 west of Ida Grove. After passing through Ida Grove together with US 59, they separate east of Ida Grove. Iowa 175 passes east through Arthur and at Odebolt, meets Iowa 39. Further east, Iowa 175 meets US 71. Iowa 175 and US 71 run east, then south, then east again concurrently through Lake View and Ulmer before separating at Auburn.