High Quality Content by WIKIPEDIA articles! M-120 is a state trunkline highway in the US state of Michigan in the southwest Lower Peninsula. The highway runs northeast from Muskegon to Hesperia. In between, the road passes through suburban Muskegon, forests and farmland. Some 5,900–26,000 vehicles use the highway each day on average as it runs long a series of roads that follow county lines in the area.