Mattawa River

Mattawa River
Petite Rivière
Pimisi Bay on the Mattawa River
Mattawa River basin map
EtymologyAlgonquin language
Location
CountryCanada
ProvinceOntario
DistrictNipissing
Physical characteristics
SourceTrout Lake
 • locationNorth Bay, Ontario
 • coordinates46°18′48″N 79°16′09″W / 46.31333°N 79.26917°W / 46.31333; -79.26917
 • elevation198.5 m (651 ft)
MouthOttawa River
 • location
Mattawa, Ontario
 • coordinates
46°19′13″N 78°42′26″W / 46.32028°N 78.70722°W / 46.32028; -78.70722
 • elevation
148 m (486 ft)
Length76 km (47 mi)
Basin size1,170 km2 (450 sq mi)
Basin features
ProgressionOttawa RiverSt. Lawrence RiverGulf of St. Lawrence
River systemOttawa River drainage basin
Tributaries 
 • rightKaibuskong River, Amable du Fond River

The Mattawa River is a river in central Ontario, Canada. It flows east from Trout Lake east of North Bay and enters the Ottawa River at the town of Mattawa. Counting from the head of Trout Lake, it is 76 kilometres (47 mi) long. The river's name comes from the Algonquin word for "meeting of waterways".

Two provincial parks are located along it: the Mattawa River Provincial Park stretches along both sides of the river's banks for almost its full length; and Samuel de Champlain Provincial Park, located about 10 kilometres (6.2 mi) from the river's end.