M-25 is a state trunkline highway in the US state of Michigan. The route follows an arc-like shape closely along the Lake Huron shore of the Thumb in the eastern Lower Peninsula between Port Huron and Bay City. It serves the lakeshore resorts along Lake Huron and Saginaw Bay and generally lies within sight of the lake and the bay. All is surface road and generally scenic, except for the freeway segment near the junction with Interstate 75 (I-75) and connection into the US Highway 10 (US 10) freeway. Between Port Huron and Port Austin it is the north–south highway was formerly US 25 before the designation was removed. Between Port Austin and Bay City it is an east–west route that appeared on some maps as US 25 and on some maps as M-25. Since the 1970s, when all of US 25 was deleted north of Cincinnati, Ohio, it is entirely signed as M-25. Route description North to Port Austin The starting point of M-25 at a junction with Business Loop I-69/Business Loop I-94 (BL I-69/BL I-94) in Port Huron. M-25 is part of the Lake Huron Circle Tour for its entire length. From here M-25 heads north on Pine Grove Avenue until meeting M-136. At this intersection, M-25 turns north on 24th Avenue to Lakeshore Road then runs parallel to the Lake Huron shoreline. In the community of Lakeport, M-25 passes through Lakeport State Park. Past the park, M-25 changes names from Lakeshore Road to Kimball Road temporarily. M-25 intersects the east end of M-90 blocks from Lake Huron in Lexington. There are public beaches in Lexington and in Port Sanilac. M-25's street name changes after the M-46 intersection to that of North Lakeshore Road. The Huron Shores Golf Club is located off the highway north of Port Sanilac at the intersection of Snover Road. Sanilac County has established the Sanilac County Park at the intersection of Downington Road and M-25 south of Richmondville. North of Forestville M-25 is once again called South Lakeshore Road as the highway crosses into Huron County. Wagener County Park is located off M-25 in the community of Helena. M-25 begins to curve to the northwest in Sand Beach near the Rock Falls Cemetery. In the city of Harbor Beach, M-25 is called Huron Avenue and meets M-142 for the first of two occasions. Here is the Harbor Beach Golf Course on the south