As the freeway continues northward, US 31 intersects the western end of M-20 in New Era in Oceana County. The landscape in this area is dominated by forest land as the trunkline crosses the Hart-Montague Trail State Park, a linear state park that follows a bike trail in the area. North of the trail crossing, US 31 has a business spur for Hart that runs east into that town; north of this interchange, the freeway crosses the Pentwater River near the community of Pentwater which also has its own business loop.