Rivière Matawin is a 161-kilometre (100-mile) river flowing west to east through the administrative regions of Lanaudière and Mauricie in Quebec, Canada. Originating at Matawin Lake within the Rouge-Matawin Wildlife Reserve at an elevation of 491 metres (1,611 feet), the river descends through a broad watershed of 5,560 square kilometres before emptying into the Saint-Maurice River near Shawinigan at an elevation of 101 metres (331 feet). Along its course, the Matawin feeds the Taureau Reservoir, which is surrounded by the Regional Park of Taureau Lake. The river is the primary tributary of the Saint-Maurice River, and its watershed has been shaped by a long history of forestry activity dating back to the mid-19th century, with tourism and outdoor recreation — including fishing — playing an important secondary role in the region's character.