Thunder Bay National Marine Sanctuary and Underwater Preserve is a United States National Marine Sanctuary on Lake Huron's Thunder Bay, within the northeastern region of the U.S. state of Michigan. It protects an estimated 116 historically significant shipwrecks ranging from nineteenth-century wooden side-wheeler paddle steamers to twentieth-century steel-hulled steamers. There are a great many wrecks in the sanctuary, and their preservation and protection is a concern for United States Government policymakers. The landward boundary of the sanctuary extends from the western boundary of Presque Isle County to the southern boundary of Alcona County. The sanctuary extends east from the lakeshore to the international border. Alpena is the largest city in the area.

History

The National Oceanic and Atmospheric Administration established Thunder Bay National Marine Sanctuary and Underwater Preserve on June 22, 2000. It became the thirteenth national marine sanctuary overall and first on the Great Lakes. Original boundaries followed that of Alpena County to 83 degrees west longitude totaling 448 sqmi. In 2014 it was expanded to 4300 sqmi. The marine sanctuary contains many shipwrecks, such as the hull of package freighter SS Pewabic.

Great Lakes Maritime Heritage Center

Tied to the sanctuary is the Great Lakes Maritime Heritage Center. The museum, located in Alpena on the Thunder Bay River, features exhibits about local shipwrecks and the Great Lakes, an auditorium, an archaeological conservation laboratory, and education areas.

Visitation

Thunder Bay National Marine Sanctuary offers a variety of recreational activities for visitors. The sanctuary is renowned for its exceptional shipwreck diving experiences, suitable for both novice and experienced divers. Several charter services provide guided dives to the sanctuary's shipwrecks, ensuring safe and educational experiences. Boating is another popular activity, with numerous boat launches and marinas available in the area.