Saint Louis River

The Saint Louis River is the largest U.S. river flowing into Lake Superior. It runs 192 miles from its source 13 miles east of Hoyt Lakes and drains a watershed of about 3,634 square miles. The river flows southwest out of the Superior National Forest to Floodwood, then turns southeast past Brookston, Cloquet, Scanlon and Thomson. Between Duluth and Superior, Wisconsin, it becomes a freshwater estuary. Its width ranges from 75 to 600 feet. Minnesota Power began using the river for hydropower near Duluth in 1906 and runs the Knife Falls, Scanlon, Thomson and Fond du Lac hydroelectric stations on it. Reservoirs on the Whiteface and Cloquet rivers affect flow on the lower river.

The Minnesota DNR manages the river as the St. Louis River State Water Trail, which has three segments. Its accesses include the Skibo Mill, County Road 95, Paupores and Brookston sites. Between Skibo Mills and Highway 100, boulder beds and Class I-II rapids can make the river impassable at medium to low water. The stretch between Scanlon and Thomson Reservoir holds Minnesota's only whitewater rafting. Some rapids within Jay Cooke State Park are open only to expert whitewater kayakers, and several dams on the lower river have portage routes. From Fond du Lac Dam to Lake Superior the river is the St. Louis River Estuary National Water Trail, designated in October 2020, with 11 paddling loops.

The DNR lists walleye, northern pike, smallmouth bass and channel catfish among the river's fish. The lower river was designated a Great Lakes Area of Concern in 1987 because of contaminated sediment, and sturgeon restoration has been under way since 1983.