<Tr> <Td> - average </Td> <Td> 16,800 m / s (590,000 cu ft / s) </Td> </Tr> <Tr> <Td_colspan="2"> Map of the Saint Lawrence / Great Lakes Watershed </Td> </Tr> <P> The Saint Lawrence River (French: Fleuve Saint - Laurent; Tuscarora: Kahnawáʼkye; Mohawk: Kaniatarowanenneh, meaning "big waterway") is a large river in the middle latitudes of North America . The Saint Lawrence River flows in a roughly north - easterly direction, connecting the Great Lakes with the Atlantic Ocean and forming the primary drainage outflow of the Great Lakes Basin . It traverses the Canadian provinces of Quebec and Ontario, and is part of the international boundary between Ontario, Canada, and the U.S. state of New York . This river also provides the basis of the commercial Saint Lawrence Seaway . </P> <P> The Saint Lawrence River begins at the outflow of Lake Ontario and flows through Gananoque, Brockville, Morristown, Ogdensburg, Massena, Cornwall, Montreal, Trois - Rivières, and Quebec City before draining into the Gulf of Saint Lawrence, the largest estuary in the world . The estuary begins at the eastern tip of Île d'Orléans, just downstream from Quebec City . The river becomes tidal around Quebec City . </P>

Where is the st. lawrence river in canada