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
Lake Superior National Estuarine Research Reserve county, state, and university entities. The Reserve is sponsored by the Cooperative Extension division of University of Wisconsin-Extension and hosted at the University of Wisconsin-Superior. Reserve offices and research facilities are on Barker's Island in Superior Bay, part of the Duluth-Superior harbor. The Lake Superior Reserve site represents a previously unrepresented biogeographic region within the National Estuarine Research Reserve System – the Great Lakes, Lake Superior subregion. The Lake Superior Reserve and the Old Woman Creek (Lake Erie in Ohio) are the only Great Lakes freshwater estuaries in the Reserve System. This subregion contains all of Lake Superior and its