Iowa Route 13 is a highway running from the east side of the Cedar Rapids area north to a junction west of Marquette and Prairie du Chien, Wisconsin. It's a north-south route in eastern and northeastern Iowa. The southern end is at a trumpet interchange with US Route 30; this trumpet interchange is where US Route 151 splits northward from the western leg of US Route 30. That is to say, the southern start of Iowa Route 13 is concurrent with US Route 151. That concurrency flanks the eastern side of Cedar Rapids, then in the satellite town of Marion, US Route 151 turns northeasterly to head independently away from the area. Iowa Route 13 continues north until its northern terminus at US Route 52 west of Marquette, Iowa. That northern endpoint is less than a mile south of US Route 18.