St. Marys River (Michigan–Ontario) St. Marys River (Michigan–Ontario) The St. Marys River (), sometimes written as the St. Mary's River, drains Lake Superior, starting at the end of Whitefish Bay and flowing southeast into Lake Huron, with a fall of . For its entire length it is an international border, separating Michigan in the United States from Ontario, Canada. The twin cities of Sault Ste. Marie, Ontario, and Sault Ste. Marie, Michigan are connected across the St. Marys River by the Sault Ste. Marie International Bridge. The St. Marys Rapids are just below the river's exit from Lake Superior and can be bypassed by
Sault Ste. Marie Canal 1870, a National Historic Event, portaged nearby, prior to the canal's construction, and was the major reason for its creation. Sault Ste. Marie Canal The Sault Ste. Marie Canal is a National Historic Site in Sault Ste. Marie, Ontario, and is part of the national park system, managed by Parks Canada. It includes a lock to bypass the rapids on the St. Marys River. The first canal on the site opened in 1798, but was destroyed in 1814 during the War of 1812. The latest canal dates to 1895, and formed part of the shipping route from the Atlantic Ocean