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, Michigan route very similar to I-75. Commercial airline service is provided to the city by the Chippewa County International Airport in Kinross, about south. Smaller general aviation aircraft also use the Sault Ste. Marie Municipal Airport about one southwest. Sault Ste. Marie was the namesake of the Minneapolis, St. Paul and Sault Ste. Marie Railway, now the Soo Line Railroad, the U.S. arm of the Canadian Pacific Railway. This railroad had a bridge parallel to the International Bridge crossing the St. Marys River. The Soo Line has since, through a series of acquisitions and mergers of portions of the system, been