View Below the Soo, Soo Locks, Michigan Postcard

The Soo Locks allow ships to travel between Lake Superior and the lower Great Lakes. The locks pass an average of 10,000 ships per year. This is achieved in spite of the locks being closed during the winter from January through March, when ice shuts down shipping on the Great Lakes. The winter closure period is used to inspect and maintain the locks. The locks bypass the rapids of the St. Marys River where the water falls 21 feet from Lake Superior. Sault Ste. Marie gives its name to both the Canadian and U.S. cities at the site, in Ontario and Michigan, respectively. The Sault Ste. Marie International Bridge between the United States and Canada permits vehicular traffic to pass over the locks.