The Great Lakes water resource region is one of 21 major geographic areas, or regions, in the first level of classification used by the United States Geological Survey to divide and sub-divide the United States into successively smaller hydrologic units. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers.
The Great Lakes region, which is listed with a 2-digit hydrologic unit code (HUC) of 04, has an approximate size of , and consists of 15 subregions, which are designated with the 4-digit HUCs 0401 through 0415.
This region includes the drainage within the United States that ultimately discharges into: (a) the Great Lakes system, including the lake surfaces, bays, and islands; and (b) the St. Lawrence River to the Riviere Richelieu drainage boundary. It encompasses parts of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin.
List of water resource subregions Subregion HUC Subregion Name Subregion Description Subregion Location Subregion Size Subregion Map 0401 Western Lake Superior Subregion The drainage into Lake Superior within the United States from the Ontario-Minnesota international boundary to and including the Montreal River Basin. Michigan, Minnesota, and Wisconsin. 0402 Southern Lake Superior–Lake Superior Subregion The drainage into Lake Superior within the United States from the Montreal River Basin boundary to the Soo Locks at Sault Sainte Marie, and Lake Superior within the United States, including its bays and islands. Michigan, Minnesota, and Wisconsin. 0403 Northwestern Lake Michigan Subregion The drainage into Lake Michigan from the Milwaukee River Basin boundary to the Manistique River Basin boundary. Michigan and Wisconsin 0404 Southwestern Lake Michigan Subregion The drainage into Lake Michigan from the St. Joseph River Basin boundary to and including the Milwaukee River Basin. Illinois, Indiana, Michigan, and Wisconsin. 0405 Southeastern Lake Michigan Subregion The drainage into Lake Michigan from and including the St. Joseph River Basin to and including the Grand River Basin. Indiana and Michigan. 0406 Northeastern Lake Michigan–Lake Michigan Subregion The drainage into Lake Michigan from the Grand River Basin boundary to and including the Manistique River Basin, and Lake Michigan, including its Bays and Islands. Illinois, Indiana, Michigan, and Wisconsin. 0407 Northwestern Lake Huron Subregion The drainage into Lake Huron within the United States from the Soo Locks at Sault Sainte Marie to and including the Au Sable River Basin. Michigan 0408 Southwestern Lake Huron–Lake Huron Subregion The drainage into Lake Huron within the United States, from the Au Sable River Basin boundary to the St. Clair River Basin boundary at the mouth of Lake Huron, and Lake Huron within the United States, including its bays and islands. Michigan 0409 St. Clair–Detroit Subregion The St. Clair and Detroit River Basins within the United States from the mouth of Lake Huron to and including the Huron River Basin, and Lake St. Clair within the United States. Michigan 0410 Western Lake Erie Subregion The drainage into Lake Erie from the Huron River Basin boundary to and including the Vermilion River Basin. Indiana, Michigan, and Ohio. 0411 Southern Lake Erie Subregion The drainage into Lake Erie from the Vermilion River Basin boundary to and including the Ashtabula River Basin. Ohio and Pennsylvania. 0412 Eastern Lake Erie–Lake Erie Subregion The drainage into Lake Erie within the United States from the Ashtabula River Basin boundary to and including the Niagara River Basin, and Lake Erie within the United States, including its bays and islands. Michigan, New York, Ohio, and Pennsylvania. 0413 Southwestern Lake Ontario Subregion The drainage into Lake Ontario from the Niagara River Basin boundary to and including the Genesee River Basin. New York and Pennsylvania. 0414 Southeastern Lake Ontario Subregion The drainage into Lake Ontario from the Genesee River Basin boundary to and including the Stony Creek Basin. New York 0415 Northeastern Lake Ontario–Lake Ontario–St. Lawrence Subregion The drainage into Lake Ontario and the St. Lawrence River Basin within the United States from the Stony Creek Basin boundary to and including the English River Basin, and Lake Ontario within the United States, including its bays and islands. New York
See also
List of rivers in the United States Water resource region
External links
References