Smallest and easternmost of the Great Lakes of North America.
Bounded by New York and Ontario, and with the U.S.-Canada border passing through it, the lake is roughly elliptical; its major axis, 193 mi (311 km) long, lies nearly east to west, and its greatest width is 53 mi (85 km). The Niagara River is the lake's main feeder. There are five islands at its eastern end, where the lake discharges into the St. Lawrence River near Kingston, Ont. The Welland Canal and the Niagara River connect it to Lake Erie to the southwest. It was visited by Samuel de Champlain in 1615; its early French name was Lac Frontenac. Ports on the lake include Toronto and Hamilton , Ont., and Rochester and Oswego, N.Y.