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St. Louis River Area of Concern


About the St. Louis River River AOC

Largest tributary to Lake Superior

The largest U.S. tributary to Lake Superior, the St. Louis River drains 3,634 square miles, entering the southwestern corner of the lake between Duluth, Minnesota, and Superior, Wisconsin. 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 in its lower reaches.

As it approaches Duluth and Superior, the river takes on the characteristics of a 12,000-acre freshwater estuary.

Map showing the St. Louis River AOC boundary
Map showing the St. Louis River AOC boundary.

The AOC boundary includes the lower 39 miles of the St. Louis River, from upstream of Cloquet, Minnesota, to its mouth at the Duluth/Superior Harbor, and that portion of the watershed; the Nemadji River watershed; and the western portion of Lake Superior approximately 10 miles from the mouth of the river (see map).

The upper estuary has some wilderness–like areas, while the lower estuary is characterized by urban development, an industrial harbor and a major port. The lower estuary culminates in the Duluth–Superior Harbor, which is one of the more heavily used ports on the Great Lakes. In 1987, concerns over environmental quality conditions prompted the designation of the lower 39 miles of St. Louis River as one of 43 Great Lakes Areas of Concern.

Historical actions such as improper municipal and industrial waste disposal and unchecked land use practices, including dredging and filling of aquatic habitat and damaging logging practices, contributed to the complex set of issues facing the AOC at the time it was listed.

Major funding for many of the projects in the St. Louis River AOC comes from the Great Lakes Restoration Initiative administered by the U.S. EPA.

Community Engagement

Community Advisory Committee (CAC)

Created in 1996 as a nonprofit, the St. Louis River Citizens Action Committee's (SLRCAC) primary focus and efforts was to foster communication between public and tribal agencies, industry groups and community stakeholders in the implementation of the RAP. The CAC also advocates and sponsors stewardship efforts as well as promotes sound management of the resources provided by the St. Louis River, Lake Superior and their watersheds.

In 2009, the SLRCAC began doing business as the St. Louis River Alliance. Alliance members include individuals, families, businesses, organizations, local and tribal governments – all helping to support our work to improve the St. Louis River.

St. Louis River Alliance
394 South Lake Avenue, Suite 321
Duluth MN 55802
Office Phone: 218–733–9520
Office Fax: 218–723–4794
St. Louis River Alliance website

St. Louis River Estuary: The Stories and the Science

Visit The Stories and the Science website to 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.

Get Involved

To learn more about AOC community events, volunteer opportunities and more, check out these links.



A "No Swimming" sign was removed in 2005 after remedial action at Hog Island Inlet was completed.
A "No Swimming" sign was removed in 2005 after remedial action at Hog Island Inlet was completed.

The majority of the beneficial use impairments (BUIs) listed for the St. Louis River AOC are due to historic habitat loss from the extensive filling of wetlands and dredging of shallow aquatic habitat, and releases of waste materials that contaminated the sediments and water in the estuary. Some sediment–derived contaminants also appear to be carried by the water column to Lake Superior, the most pristine Great Lake. The States are responsible for implementing Remedial Action Plans to remove the impairments and delist the St. Louis River as an Area of Concern.

Of the 14 beneficial uses, nine are listed as impaired for the St. Louis River.

  • Restrictions on fish and wildlife consumption
  • Degradation of fish and wildlife populations - BUI removed Jan. 2023
  • Fish tumors or other deformities - BUI removed Feb. 2019
  • Degradation of benthos
  • Restrictions on dredging activities
  • Excessive loading of nutrients and sediments - BUI removed April 2020
  • Beach closings and body contact
  • Degradation of aesthetics - BUI removed Aug. 2014
  • Loss of fish and wildlife habitat

Timeline for removing impairments

Final BUI removal packages with cover letters

AOC Plans

AOC plans

The St. Louis River Area of Concern continues to make progress toward delisting each year. The Remedial Action Plan is an annual document that provides an update on the AOC work and outlines the strategy for completing the remaining actions.



Feature Videos

The following videos highlight the basic principles of Areas of Concern while highlighting some projects in the St. Louis River Estuary.

Restoring Wild Rice in the St. Louis River Estuary

Wild rice, or manoomin in Ojibwe, is a nutritional grain that is central to the cultural identity of the Ojibwe people. It's also an important ecological resource that's largely been lost in the St. Louis River estuary. This video shows how we are working with the Fond du Lac Band of Lake Superior Chippewa, the Great Lakes Indian Fish & Wildlife Commission and other partners to restore 275 self-sustaining acres in the AOC.

Protecting Dunes and Restoring and Piping Plover Habitat on Wisconsin Point

One project at this unique and important place protected sensitive dune habitats and historical sites, while also improving public beach access for people who are mobility challenged. Another project created 14 acres of new habitat for the endangered Piping Plover at the DNR-owned Wisconsin Point Bird Sanctuary.

Restoring Barker's Island Beach in Superior

The beach at Barker's Island in the city of Superior now has cleaner water thanks to added native plants and improved access for people to enjoy the water through ecologically sound parking and beach upgrades. This project is part of the larger effort to restore the St. Louis River AOC.

Additional Videos

The following videos are from the Minnesota DNR.



Wisconsin leads approximately 25 management actions in the St. Louis River AOC. Of the 80 total actions, 53 have been completed. These actions include habitat restoration, sediment cleanup and monitoring and assessment projects.

Shipping on the St. Louis River
Shipping on the St. Louis River.
Map showing remediation and restoration sites in the St. Louis River AOC.

Wisconsin Project Fact Sheets


Coordination With Minnesota

Minnesota leads approximately 31 actions in the St. Louis River AOC. To learn more see:

Completed Cleanup Sites



Matt Steiger
St. Louis River AOC Coordinator
Wisconsin Dept. of Natural Resources
Superior WI

Melissa Sjolund
St. Louis River AOC Coordinator
Minnesota Dept. of Natural Resources
Duluth MN

Barb Huberty
St. Louis River AOC Coordinator
Minnesota Pollution Control Agency
Duluth MN

Rick Gitar
Water Regulatory Specialist
Fond du Lac Resource Management – Fond du Lac Band of Lake Superior Chippewa in Minnesota
Cloquet Minnesota