Great Lakes other lakes as "the lower lakes", because they are farther south. Sailors of bulk freighters transferring cargoes from Lake Superior and northern Lake Michigan and Lake Huron to ports on Lake Erie or Ontario commonly refer to the latter as the lower lakes and Lakes Michigan, Huron, and Superior as the upper lakes. This corresponds to thinking of Lakes Erie and Ontario as "down south" and the others as "up north". Vessels sailing north on Lake Michigan are considered "upbound" even though they are sailing toward its effluent current. Lakes Huron and Michigan are sometimes considered a single lake, called
Eastern Great Lakes and Hudson Lowlands (ecoregion) addition the World Wildlife Fund developed its own classification system, in which much of this region is called the Eastern Great Lakes lowland forests. Eastern Great Lakes and Hudson Lowlands (ecoregion) The Eastern Great Lakes and Hudson Lowlands region extends along the south shores of Lake Erie and Lake Ontario and the St. Lawrence River to Lake Champlain, and south down the Hudson River. It is primarily within the state of New York. In the north it meets the Mixedwood Plains Ecozone of Canada. It is mostly temperate deciduous forest and agricultural land. It is one of the 104 Level