Duluth-Superior Harbor
(as shown in this aerial map here)is
located within the confines of the cities of Duluth, Minnesota (St. Louis
County), and Superior, Wisconsin (Douglas County).
Duluth lies on the
western shore of Lake Superior and St. Louis Bay, in northeastern Minnesota.
Duluth and Superior, Wis.--which lies across the bay--are part of a
metropolitan area with a population of 239,971. Duluth is the third-largest
city in Minnesota. Only Minneapolis and St. Paul have more people. This city is
built on a steep slope that rises about 800 feet (240 meters) above the shore
of Lake Superior.
Duluth-Superior Harbor area occupies roughly 32
square miles and has over 100 miles of waterfront. Duluth-Superior Harbor has
two inlets to Lake Superior and a constriction separating the inner and outer
harbor. The harbor is protected by a natural barrier, a sand and gravel bar
just over six miles in length, which is transected by the Duluth Ship Canal and
the Superior Entry providing access to Lake Superior. This barrier is known as
Minnesota Point north of the Superior Entry providing access to Lake Superior,
and as Wisconsin Point to the south. Two inner splits, Rices Point and Conners
Point, divide the port into inner and outer harbors. The inner harbor is
developed within St. Louis Bay and on up to the St. Louis River.
Duluth-Superior Harbor is a major
Great Lakes port and a transportation center for products of the upper Midwest.
It is connected to the Atlantic Ocean by way of the St. Lawrence Seaway. It is
the busiest freshwater port in North America.
Over 55 docks lie along the 47 miles
(76 kilometers) of harbor frontage. Port facilities include iron ore docks,
coal docks, and grain elevators. Iron ore and coal are the chief products
shipped from Duluth to other parts of the United States. Grain is the main international
export. Important industries in Duluth include machine shops; paper mills; and
printing, publishing, and food-processing operations.
An unusual feature of the port is a
picturesque lift bridge that crosses the Duluth ship canal. The canal was constructed
in 1871 by cutting through a sand bar called Minnesota Point. It was built to
provide access to the Minnesota portion of St. Louis Bay.
Duluth and its surrounding area make
up an attractive vacation center. Skyline Parkway along the heights of
the city offers scenic views of Duluth, Superior, and Lake Superior. The city
has favorable conditions for summer and winter sports. The average temperature
in July is 65 °F (18 °C), and the average temperature in January is 6 °F (-14
°C). The city is the gateway to the scenic North Shore of Lake Superior.
Duluth was named in honor of Daniel
Greysolon, Sieur Duluth (or Du Lhut), a French explorer and trader who visited
the site about 1679. In the 1700's, British traders replaced the French traders
in the area. In 1817, John Jacob Astor's American Fur Company started a trading
post at Fond du Lac, in what is now western Duluth. More people began to come
to the area in the 1850's. Duluth was incorporated as a city in 1870. The
population fell in the mid-1870's, and Duluth lost its status as a city. By
about 1880, Duluth again began to grow swiftly, as lumbering and sawmill
activities increased. It was incorporated as a city again in 1887. Another
period of growth began in the 1890's, when iron ore shipping developed.
The St. Louis River, the largest U.S. tributary to Lake Superior, drains 3,634 square miles, entering the southwestern corner of the lake between Duluth, MN and Superior, WI. The river flows 179 miles through three distinct areas; coarse soils, glacial till and outwash deposits at its headwaters; a deep narrow gorge at Jay Cooke State Park; and red clay deposits at its lower reaches. As the river approaches Duluth and Superior it takes on the characteristics of a 12,000 acre (4856 hectare) freshwater estuary. While the upper part of the estuary has some wilderness-like qualities, the lower portion is decidedly urban.
The lower St. Louis River is one of 42 Areas of Concern (AOC) in the Lake Superior basin. An AOC is a site that has serious environmental pollution problems that require remedial action and the development of a Remedial Action Plan (RAP) to outline ways to restore the area. See EPA GLNPO for more information on the Great Lakes AOCs. The Minnesota Pollution Control Agency has a web page that discusses contaminated sediments within the St Louis River.
A large publicly owned wastewater treatment plant (Western Lake Superior Sanitary District, WLSSD) discharges into St. Louis River and the river carries a heavy load of suspended sediments from non-point sources. The river also has a number of sites known to contain contaminated sediments.
The lower St Louis provides good fish habitat and is an excellent warm water fishery. However, the recent invasion of exotic fish (Eurasian ruffe and round goby) may threaten native fish populations (see MN Sea Grant exotic species ).