Gratiot Light, the first lighthouse in the state of Michigan, was constructed north of Fort Gratiot in 1829 by Lucius Lyon, who later became one of Michigan's first U.S. Senators.
The Fort Gratiot Light marks the entrance to the St. Clair River from Lake Huron (going south) in the southern portion of Michigan's Thumb. The light is still active and the grounds are an active Coast Guard facility, but it has recently been handed over to the Port Huron Museum. It is the oldest surviving lighthouse in Michigan. There is also a public beach and park on the property, known as Lighthouse Beach.