St. Louis River

About

St. Louis River, Minnesota — 1679 Daniel Greysolon du Lhut, 1840s-1880s Iron Mining, 2010s St Louis River Watch 200-mi. The St. Louis rises in northeastern Minnesota and runs 192 miles through St. Louis and Carlton Counties, ending at Lake Superior's southwestern corner between Duluth and Superior, Wisconsin. It is the largest U.S. tributary to the lake, gathering a 3,634-square-mile watershed before it arrives. USGS gauge 04024000 records an average flow of 2,800 CFS, with paddlers finding the river most workable between roughly 1,000 and 5,000 CFS. The character changes sharply along its length: the Thomson Dam to Jay Cooke reach is 8 miles of Class III–IV premier whitewater, Jay Cooke to Fond du Lac runs 10 miles of Class II through a slate gorge, and the upper river from Forbes to Floodwood offers 50 miles of Class I flatwater.

Long before the mills, the river was an Ojibwe travel corridor connecting the interior lakes to Lake Superior. Fond du Lac, at the river's mouth, was a major fur trade rendezvous site, and the Fond du Lac Band of Lake Superior Chippewa maintains a reservation along the river today. European names entered the record in 1679, when Daniel Greysolon, Sieur du Lhut — born in Lyons, France, around 1639 — ventured into the Lake Superior country and led an expedition into the region. Duluth carries his name.

The river's modern story turns on industry and its consequences. Through the 1880s to the 1920s, the St. Louis drove Duluth's rise as a lumber and shipping powerhouse; millions of board feet of white and red pine were floated down to sawmills at its mouth. In 1907, the Thomson Dam was built for hydropower, holding back the Thomson Reservoir north of Thomson in Carlton County. That legacy left a chemical mark: investigations have found elevated concentrations of dioxins and furans distributed widely through the reservoir's sediments. The accumulated burden of a century of milling and manufacturing culminated in the 1987 designation as one of 43 Great Lakes Areas of Concern over its environmental quality.

Recovery has been a long project. Early hydrological work reached back to USGS surveys of the 1870s–1890s and gauging-station establishment in the 1880s–1910s, followed by state water pollution control studies in the 1950s–1970s and Clean Water Act assessments from 1972 onward. From 2010 to the present, the Minnesota DNR, working with local watershed partnerships, has addressed more than 100 years of logging, agricultural, and industrial impacts. Recent outcomes include streambank stabilization from 2015 to 2024, native fish restocking from 2017 to 2024, a nutrient reduction strategy implemented from 2018 to 2024, and water-quality improvements from 2020 to 2024.

Today the St. Louis works to shed its Area of Concern label, its estuary the subject of an ongoing cleanup meant to return one of Lake Superior's great waters to health. The river runs through Jay Cooke State Park and is a designated St. Louis River National Water Trail. It remains a popular trout and walleye fishing destination, supporting the Duluth, Cloquet, and Two Harbors economies. For those without their own boat, Spirit of the Land Outfitters runs kayak rentals and guided trips from Duluth.