A favorite tour for a motorcyclist is the State Highway Michigan M25. It’s a 147-mile road running from Port Huron to Bay City Michigan. With waters of Lake Huron or Saginaw Bay on one side and rolling pasture and farmland on the other, it’s one of the more interesting drives in southern Michigan.
Officially Michigan M25 is a state trunkline highway in the US state of Michigan. M-25 is part of the Lake Huron Circle Tour for its entire length.