Great Lakes Waterway River between Huron and Erie. Usually, one or more U.S. Coast Guard icebreakers help keep the water passage open for part of the fall and early winter, although shipping usually ceases for two to three months thereafter. The Great Lakes Waterway is co-administered by the governments of Canada and the United States of America. The waterway allows passage from the Atlantic Ocean to the inland port of Duluth on Lake Superior, a distance of and to Chicago, on Lake Michigan, at . Together with the Saint Lawrence Seaway, the Waterway allows both ocean-going vessels and the ore, grain and coal-bearing
Duluth Ship Canal of adverse weather. Around a thousand vessels a year ship from the Duluth–Superior port. The construction of the first locks on the St. Marys River in 1855 allowed for navigation between the lakes, and Superior Bay presented itself as an attractive harbor. From the point of view of Duluth residents, however, arrangements were less than satisfactory, as ships from that city had to pass Superior, Wisconsin on the way to the lake, as the only natural outlet was between Minnesota Point and Wisconsin Point at the far end of the bay. Also, while sheltered, the bay was not naturally as