The river begins at Crocker Bay at the northwest of Raleigh Lake, flows northwest over the Raleigh Falls, then under Ontario Highway 17 and the Canadian Pacific Railwaytranscontinentalmain line at the settlement of Raleigh. It continues northwest, takes in the right tributary Little Wabigoon River, then turns southwest back under the CP line and Highway 17 at the settlement of Taché. The river takes in the left tributary Mennin River, flows over Walker Falls, and takes in the right tributary Melgund Creek all near the settlement of Borups Corners, enters Dinorwic Lake, and flows into Wabigoon Lake, where it takes in the left tributary Crooked River. The Wabigoon River exits the lake at the northwest at Dryden, and flows northwest, through Wainwright Township dam and generating station, takes in the left tributary Eagle River, passes under Ontario Highway 105 at Upper Falls, then under Ontario Highway 609 and the Canadian National Railway transcontinental main line and over Quibell Dam the latter three at the settlement of Quibell. It then heads northwest to Clay Lake, takes in the left tributary Canyon River at Canyon Stretch, passes through Segise Lake, and reaches its mouth at Ball Lake on the English River, which flows via the Winnipeg River and Nelson River to Hudson Bay.
Mercury pollution
In 1962, Dryden Chemical Company began operating a chloralkali process plant in Dryden that produced chlorine and sodium hydroxide which were used at the nearby Dryden Pulp and Paper Company for bleaching pulp. Dryden Chemical Company dumped its waste water containing mercury into the Wabigoon River. The mercury pollution spread throughout the downstream Wabigoon-English River system. The mercury entered the food chain and accumulated in fish which were a major part of the diet for First Nations people on reserves at Grassy Narrows and Whitedog. This caused severe mercury poisoning with symptoms including neurological problems and birth defects among these people and also resulted in the closure of a commercial fishery and a fishing lodge in the area. In 1985, an agreement was signed which committed the federal and provincial governments and the two private companies involved to provide compensation. Dissolved mercury is now low in the river system and past concentrations are recorded in the sediments of Clay Lake. Elevated concentrations persist in larger, older fish in the river system, although concentrations have dropped considerably over the past few decades
