F-32 (McKinley Rd.) west of Mio is the northern road along the Au Sable River. The western third has some residential sections but the eastern two thirds is undeveloped forest with very little traffic. The sweepers and twists are very good for the area. Take F-32 east out of Mio for 16 miles until it turns into Au Sable Rd. then turn around and it take it back to Mio.