Encyclopedia > Thunder Bay National Marine Sanctuary
The Thunder Bay National Marine Sanctuary and Underwater Preserve is a U.S. National Marine Sanctuary on the Thunder Bay of Lake Huron within the U.S. state of Michigan. The 448-square mile sanctuary and underwater preserve protects an estimated 116 historically significant shipwrecks ranging from nineteenth century wooden side-wheelers to twentieth century steel-hulled steamers. The Thunder Bay is the thirteeneth National Marine Sanctuary designated by the National Oceanic and Atmospheric Administration.
The landward boundary of the the sanctuary extends from the northern boundary of Alpena County near Middle Island, to its southern boundary near South Point. sanctuary extends east from the lakeshore to longitude 83 degrees west. Alpena is the largest city in the area.