M-142 begins just a few miles south of Bay Port at an intersection with
M-25 near the Bay Port Cemetery, about two-thirds of a mile (1.1 km) inland from Saginaw Bay. From there, the road travels eastward through farm country on Pigeon Road. The highway follows a direct course over the
Pigeon River to the village of
Pigeon, when M-142 turns south on Main Street to exit town. South of town, the Pigeon Road name resumes, and after about , M-142 turns back eastward near the Grand Lawn Cemetery. The road then continues eastward through more farms to
Elkton, diverting off a direct course to cross a line of the
Huron and Eastern Railway on the east side of town. North of Bad Axe, M-142 leaves Pigeon Road to turn southward along Van Dyke Road for about mile and a half (2.4 km). Along this section, the highway
runs concurrently with
M-53 into town. At the intersection with Huron Avenue, M-142 turns east and M-53 turns west, ending the overlap of the two highways. M-142 exits town and follows Sand Beach Road through farm country. About of Bad Axe, M-142 meets the northern terminus of
M-19 (Ubly Road). Continuing eastward, the highway crosses two branches of the Willow River as it passes through the
unincorporated community of
Verona. East of that location, the trunkline turns northeasterly, roughly parallel to the Rock Falls Creek, as it angles to Harbor Beach. M-142 follows State Street through town, and the trunkline terminates at the intersection with M-25 about a quarter mile (0.4 km) west of Lake Huron. No section of M-142 is listed on the
National Highway System, a network of roads important to the country's economy, defense, and mobility. ==History==