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
The Great Lakes Group provides linehandling assistance to vessels transiting the United States Army Corps of Engineers-administered and -operated Soo Locks at Sault Ste. Marie, Michigan on the St. Mary's River, the only water connection between Lake Superior and the other Great Lakes. The Soo Locks are located in the St. Mary's Rapids, where the water falls about 21 feet from the level of Lake Superior to the level of the lower lakes. Vessels must transit the Soo Locks en route to the principal ports of Duluth, Minnesota and Thunder Bay, Ontario and outbound to the sea. In 1999 Admiral Towing and Barge Company