M-209 was a state trunkline highway in the Lower Peninsula of the US state of Michigan. It was located in Leelanau County in the Sleeping Bear Dunes National Lakeshore. Until it was decommissioned, it was Michigan's shortest state highway. M-209 started at M-109 and went just over 1⁄2 mile (about 956 yards [874 m]) to Glen Haven. In 1996, M-209's designation was "abandoned", and the road was turned over to the jurisdiction of the Leelanau County Road Commission.