The
Great Lakes Basin consists of the
Great Lakes and the surrounding lands of the states of
Illinois,
Indiana,
Michigan,
Minnesota,
New York,
Ohio,
Pennsylvania, and
Wisconsin in the
United States, and the province of
Ontario in
Canada, whose direct
surface runoff and
watersheds form a large
drainage basin that feeds into the lakes. It is generally considered to also include a small area around and beyond
Wolfe Island, Ontario, at the east end of Lake Ontario, which does not drain into the Great lakes, but into the
Saint Lawrence River.