Thunder Bay, located in northwestern Lake Huron, is adjacent to one of the most treacherous stretches of water in the Great Lakes system. The area is known as "Shipwreck Alley," a name it has earned as a result of the unpredictable weather, murky fog banks, tragic collision, sudden gales, and rocky shoals that have claimed hundreds of Great Lakes vessels over the years.

Thunder Bay National Marine Sanctuary, the nation's only National Marine Sanctuary located in freshwater, protects a 448-square-mile region within this area of Lake Huron, encompassing one of America's best-preserved and historically-significant collections of nearly 200 shipwrecks. The Sanctuary also protects and interprets the remains of commercial fishing sites, historic docks, and other underwater archaeological sites, creating a protective space for the remains of a complex and evolving maritime landscape shaped by the many centuries of human use of the Great Lakes.

This Encyclopedia is meant to provide information, video clips, still images, and additional educational resources about the underwater treasures that can be found within Thunder Bay National Marine Sanctuary. We hope you find this to be a valuable resource and visit often.