River watershed

A unique monitoring site,
the St. Louis River mouth is influenced not only by river water flowing downstream but also occasionally by Lake Superior water flowing upstream due to the lake's seiche.

Saint Louis River Citizens Action Committee

The St. Louis Bay has been listed by the MPCA as impaired (fecal coliform).

It is also an Area of Concern. Learn more here.

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 or the Wisconsin DNR for information specific to the St Louis River AOC. The Minnesota Pollution Control Agency has a web page that discusses contaminated sediments within the St Louis River. St. Louis Estuary restoration efforts are updated here.

A large publicly owned wastewater treatment plant (Western Lake Superior Sanitary District, WLSSD) discharges into the 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. See our Reports page for more details.

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 ).

Beginning in 2011, a major project began entitled "Implementation Framework for Delisting the St. Louis River AOC. Funded by EPA's Great Lakes Restoration Initiative, the MPCA, MnDNR, and WiDNR are leading an effort to develop Beneficial Use Imapirment (BUI) Blueprints for cleaning up the SLR AOC. These Blueprints will complement a flurry of current GLRI-funded remediation activities to guide the complete restoration of degraded portions of the system.

SLRE data mapping app

Try our new mapping and plotting utility to explore the water quality data collected in the St Louis River estuary over the last 60 years.

“There’s no question that if not for Lake Superior, Duluth would be defined as a river city. Duluth should be defined by both the world’s greatest lake AND the world’s largest fresh water estuary. By doing so, we open up many possibilities along the River.”– Mayor Don Ness

Learn more about the vision for the St. Louis River Corridor as an outdoor recreation destination and environmental hub.

Explore the Stories of the Estuary through the eyes of people that live and work here, and delve into the Science of the interplay between humans and ecosystems. Challenge yourself with real-world Geoquests or see how Deep Maps capture the beauty and complexity of this special place.

On Friday November 1, 2013 the Swinging Bridge in Jay Cooke State Park reopened to the public after sustaining significant damage during the 2012 Solstice Flood. The reconstructed bridge includes accessibility improvements and design features that recreate some of the work performed by Civilian Conservation Corps (CCC) workers in 1934.

Hog Island Cleanup

Over 50,000 cubic yards of petroleum- contaminated sediment and soil from Newton Creek and parts of Hog Island Inlet were dug up and safely disposed. This location is part of the St. Louis River AOC.

Read about the project in this edition of the Creek News, or in this article by The Lake Voice. Read about the MPCA's blueprint for carrying out the remaining restoration activites here.

Other editions of Creek News, featuring area streams, are found here.