Humber River, river on the western side of the island of Newfoundland, Can., rising in the Long Range Mountains, inland from St. Pauls Inlet. It flows generally southward for 75 miles (121 km) over a series of falls and through several lakes, including Deer Lake, to the Humber Arm of the Bay of Islands at Corner Brook. The river and its valley form a major salmon-fishing, lumbering, hunting, and farming region. A hydroelectric plant at Deer Lake supplies power for the huge paper and pulp mills in Corner Brook, as well as for mining operations at Buchans and local sawmills. The Trans-Canada Highway and the Canadian National Railway parallel much of the Humber’s lower course.