What is the lowest natural point on the Great Lakes water surface?

Lake Ontario has the lowest natural water-surface elevation of the Great Lakes.

Its surface is about 74 metres (243 feet) above sea level, lower than the surfaces of Lakes Erie, Huron, Michigan, and Superior. The lake lies at the eastern end of the Great Lakes chain and receives water from Lake Erie through the Niagara River.

From Lake Ontario, water leaves through the St. Lawrence River and eventually reaches the Atlantic Ocean. The lake’s basin is deep, with a maximum depth of about 244 metres (802 feet), even though its surface is the lowest among the five lakes.

Elevation and depth are different measurements. Lake Superior has the highest surface elevation, while Lake Ontario has the lowest surface elevation and is not the shallowest Great Lake; Lake Erie is shallower overall.