M-231 begins along M-45 (Lake Michigan Drive) in Robinson Township near the intersection with 120th Avenue. It runs due north through a mix of farm fields and forest lands in Ottawa County. The highway is a two-lane, limited-access highway. The trunkline crosses North Cedar Drive on an overpass, and then it crosses the Grand River into Crockery Township. As it crosses the river, M-231 angles northeasterly before intersecting M-104 the latter's eastern terminus at I-96, and M-231 continues north to its own northern terminus at a new partial interchange with I-96.