Lake Ontario

Ontario, Canada

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Lake Ontario is the easternmost and smallest by surface area of the Great Lakes of North America, bordered by Ontario, Canada to the north and New York, USA to the south.

It has a surface area of approximately 7,340 square miles (19,000 square kilometers) and is about 193 miles (311 kilometers) long and 53 miles (85 kilometers) wide at its widest point.

The lake reaches a maximum depth of around 802 feet (244 meters) with an average depth of 283 feet (86 meters). It is fed mainly by the Niagara River, which drains Lake Erie, and its outlet is the St. Lawrence River flowing towards the Atlantic Ocean. The lake's shoreline, including islands, extends for about 712 miles (1,146 kilometers) and features diverse ecosystems, wetlands, and fisheries.

It plays a vital role for the surrounding populations, providing drinking water, recreation, and economic benefits. The lake experiences seasonal water level fluctuations and is known for its lake-effect snow on the southern shores during winter. Its basin supports urban centers including Toronto and contributes significantly to the Great Lakes Basin's environmental and economic system.