St. Louis River Estuary

The St. Louis River, the largest U.S. tributary to Lake Superior, travels 179 miles from the Sand Lake/Seven Beavers landscape before it meets Lake Superior above the twin ports of Duluth and Superior to form a 12,000 acre freshwater estuary – like none other in the Great Lakes.

Here, The Nature Conservancy works in Minnesota and Wisconsin with a multitude of partners to preserve and restore the area’s unusual array of high quality coastal wetlands, old growth forests, fisheries, a critical mid-continent bird fly-way and nesting ground, streams, baymouth bars and sand dunes. Wildernesses lie juxtaposed with an active harbor – the largest on the Great Lakes.

St. Louis County, Minnesota and Douglas County, Wisconsin, near Duluth and Superior.

The estuary, proper, encompasses over 12,000 acres, and the landscape supporting the adjacent estuary and its habitats covers some 260,000 acres.

Why the Conservancy Selected this Site

The Conservancy was drawn to this landscape when it looked at the biodiversity unique across all of the Great Lakes – the St. Louis Estuary stood out as unique and with great hope of ensuring long term survival and restoration of its native habitats and species. The combination of ecosystems within the St. Louis Estuary – estuarine wetland and aquatic habitats, baymouth bar complex, its importance to breeding and migratory birds, and its importance to native fish – are very unusual in Lake Superior, the Upper Midwest, the Great Lakes, and around the world.

What the Conservancy Has Done/Is Doing
Though there is much hope for this remarkable place, the Conservancy and its partners are challenged to ensure a bright future for the Estuary. Threats to the Estuary include loss of habitat due to development, commercial shipping and other sources, increased sedimentation due to development, forest management practices and other sources, competition from undesirable exotic species introduced by commercial shipping and development, exposure to contaminants from historical and current industrial activity, and water quality.

The Conservancy owns two properties as of 2003 on both sides of the state line in the Estuary. In 2002, the Conservancy assisted the City of Duluth in developing a new law establishing the Duluth Natural Areas Program, which designates for protection special natural areas owned by the city (a major landowner in the Estuary). The Conservancy is actively working to designated critical areas to this program. Activities necessary to abate the threats to the ecological integrity of the Estuary, however, challenge the Conservancy and others to develop additional strategies and partnerships.

In 2002, the St. Louis River Citizens Action Committee published the Lower St. Louis River Habitat Plan, with support from the Conservancy and others. This plan outlines specific steps to preserve and restore the critical habitats of the Estuary.

The Conservancy works with a wide variety of partners on protection and restoration in the Estuary. These partners include:

  • St. Louis River Citizens Action Committee
  • Minnesota Department of Natural Resources
  • Wisconsin Department of Natural Resources
  • Minnesota Sea Grant
  • Fond Du Lac Band of Lake Superior Ojibway
  • U.S Environmental Protection Agency
  • City of Duluth
  • City of Superior
  • Minnesota Power
  • Minnesota Ornithologists’ Union
  • U.S. Coast Guard
  • U.S. Fish and Wildlife Service
  • Natural Resources Research Institute – UMD
  • Minnesota Pollution Control Agency
  • Carlton County Soil and Water District
  • 1854 Authority
  • Douglas County
  • Numerous private citizens and companies 
Improving Habitat for Prehistoric Fish in the Estuary

In 2009, The Nature Conservancy has joined the Wisconsin and Minnesota departments of natural resources in their decades-long effort to support lake sturgeon repopulation in the St. Louis River.

This ancient bottom feeder can reach a length of more than six feet and live more than 100 years. The fish is a species of special concern in Minnesota.

Over the years, sturgeon populations have declined due to dam management, diminished water quality from industrialization and the loss of spawning and rearing habitat.

The Conservancy is assisting with a project just below the Fond du Lac dam on the main channel of the St. Louis River to improve spawning habitat conditions on 8,800 square feet of river channel.

The Conservancy’s contribution was to secure funding for the project and to arrange for almost 200 truckloads of boulders and rocks (1,500 tons) to be moved into the river.

The Minnesota Department of Natural Resources used the material to create riffles and pools that are ideal for spawning lake sturgeon and other native fish including walleye. See a video of the project.

Funding for the project is provided by the Environmental Protection Agency and the U.S. Fish and Wildlife Service through a grant from the National Fish and Wildlife Foundation.

It is one of more than 40 projects planned to improve habitat and water quality in the St. Louis River Estuary.

What to See: Plant Communities
The St. Louis Estuary includes a wide variety of plant communities. Aquatic plants, found in the wetlands and riverine systems of the Estuary, generally are adapted to fluctuations in water levels caused by the seiche (back and forth "sloshing") of Lake Superior. Upland forest plants include northern hardwood forests at Magney-Snively Park with spring ephemeral plants and old growth forests, and aspen-spruce-fir forests in Superior Municipal Forest. The baymouth bars of Wisconsin and Minnesota (Park) points include sensitive beach dune plant communities as well as old growth upland red pine forests. 

What to See: Animals
Birds and fish are the biggest attraction, although the area also is home to black bear, wolves, mink, otters, white-tailed deer and red fox. The St. Louis Estuary serves as the primary nursery for the fish found in western Lake Superior, and is home to over 45 native fish species, including walleye, lake sturgeon, muskellunge, northern pike and smallmouth bass. There are also several species of native freshwater mussels found in the Estuary.

The St. Louis Estuary is home to over 230 bird species and is a critical migratory stopover and breeding area. In addition to a multitude of songbird species, large numbers of raptors, shorebirds, waterbirds, gulls, and terns migrate through the area each spring and fall. Several factors make the Estuary an important stopover site. Many migrants will not fly over large bodies of water and thus are funneled to the Estuary at the far western end of Lake Superior. The Estuary contains large expanses of wetlands that provide important food sources and nesting habitat. The Estuary also is a rarity in that it includes open, sandy beaches for shorebirds. The diversity of habitats make the St. Louis Estuary ideal for breeding birds as well.

While the Conservancy currently owns two properties within the estuary, its efforts here focus more on working with existing landowners, such as the City of Duluth, to protect special natural areas. The estuary is easily appreciated by foot or by boat, with numerous trails and quiet waters and entry points on both sides of the estuary.

Visitors are encouraged to explore Jay Cooke State Park, Magney-Snively Park and Spirit Mountain, North Bay, Superior Municipal Forest (4000 acres), Park Point and Wisconsin Point.


The Conservancy’s "Worthington" property is located on the river in Oliver, Wisconsin, and its Magney Forest property is located adjacent to City of Duluth land on Stewart Creek in Magney-Snively Park.

There are many places from which to see, hike, paddle, peddle, walk the St. Louis Estuary environs.

In Duluth, follow Grand Avenue going west. From here you may access:

The Munger State Trail
Western Waterfront Trail
Smithville/Munger Landing
Boy Scout Landing
North Bay overlook
Perch Lake Fishing Pier
Chambers Grove Park
Jay Cooke State Park

Cross the Oliver Bridge to the Village of Oliver boat launch and Worthington property and Superior Municipal Forest (also accessible from Superior)

Skyline Parkway going west, to access:

Jay Cooke State Park
Magney-Snively Park

Cross the Route 2 Bridge to access Billings Park boat launch and Superior Municipal Forest south of Superior

Cross the Aerial Lift Bridge in Duluth and drive to the end of Park Point to access the trails and beaches of this remarkable baymouth bar and its unique plant habitats.

Cross the Route 53 (Blatnik) Bridge to Superior, left on Moccasin Mike Road, left on Wisconsin Point Road.


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