Lake Superior, the largest freshwater lake in the world, is the
northernmost, highest, and deepest of the five Great Lakes. The lake is fed by the waters of many short
swift-flowing streams and drains through the St.
Marys River into Lake Huron.
The shores of the lake are generally high, rocky, and forested. The lake is sparsely populated, especially
along the north shore.
The waters of Lake Superior are colder and form more ice than do
the other lakes. The navigation season,
shorter than the other lakes, is generally about eight months long. The actual length of the season depends
primarily on whether tonnage demands justify the expense of ice
breaking for earlier or later vessel movements.
Compared with the other Great Lakes, Lake Superior is fairly
well provided with natural harbors that provide refuge for vessels. In addition, several harbors have been
improved with breakwaters to provide the necessary protection. The most important harbor in U.S. waters on
the lake is at Duluth-Superior.
The Great Lakes Towing Company provides tug service to Lake
Superior ports, including Duluth-Superior, and Ashland with tugs stationed
in Duluth.