Saint Lawrence River
Saint Lawrence River Fleuve Saint-Laurent , Fleuve St-Laurent , St-Lawrence River, St-Laurent River Saint Lawrence River near Alexandria Bay Name origin: Saint Lawrence of Rome Countries Canada, United States Provinces Ontario, Quebec State New York Source Lake Ontario - location Kingston, Ontario / Cape Vincent, New York - elevation 74.7 m (245 ft) - coordinates 44°06′N 76°24′W / 44.100°N 76.400°W / 44.100; -76.400 Mouth Gulf of St. Lawrence / Atlantic Ocean - elevation 0 m (0 ft) - coordinates 49°30′N 64°30′W / 49.500°N 64.500°W / 49.500; -64.500 Coordinates: 49°30′N 64°30′W / 49.500°N 64.500°W / 49.500; -64.500 Length 500 km (310 mi) Excluding the estuary. Ca. 1200 km if included. Basin 1,344,200 km 2 (519,000 sq mi) [1] Discharge for below the Saguenay River - average 16,800 m 3 /s (590,000 cu ft/s) [2] Map of the Saint Lawrence/G...