Duluth, Minnesota Lakes Waterway and the Saint Lawrence Seaway. Duluth forms a metropolitan area with neighboring Superior, Wisconsin, called the Twin Ports. The cities share the Duluth–Superior harbor and together are the Great Lakes' largest port, transporting coal, iron ore (taconite), and grain. A tourist destination for the Midwest, Duluth features the United States' only all-freshwater aquarium, the Great Lakes Aquarium; the Aerial Lift Bridge, which spans the Duluth Ship Canal into the Duluth–Superior Harbor; and Minnesota Point (known locally as Park Point), the world's longest freshwater baymouth bar, spanning . The city is also the starting point for vehicle trips along
St. Paul and Duluth Railroad Northern merger, as it paralleled another line of the Great Northern Railway. Most of the line therefore was abandoned and many segments were turned into rail trails. The disposition of those segments is as follows: St. Paul and Duluth Railroad The St. Paul and Duluth Railroad was reorganized from the Lake Superior and Mississippi Railroad in 1877. It was bought by the Northern Pacific in 1900. Known to this day as the "Skally Line", it operated from Saint Paul to Duluth, Minnesota, with branches to Minneapolis, Taylors Falls, Kettle River, and Cloquet, in Minnesota, and Grantsburg and Superior in Wisconsin.