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Thunder Bay National Marine Sanctuary

Thunder Bay National Marine Sanctuary

Located at Alpena, Thunder Bay NMSUP protects one of the nation’s best preserved and historically significant collections of shipwrecks. The 448-square-mile site, the only freshwater national marine sanctuary in the U.S., is jointly managed by the Michigan Historical Center and the National Oceanic and Atmospheric Administration.

Dates and Hours

Monday through Saturday, 10 A.M. – 5 P.M., and Sunday, 12 P.M. – 5 P.M., year round.


Admission to the national marine sanctuary is free.


View Thunder Bay National Marine in a larger map

Contact Us

Telephone: (989) 356-8805.