Great Lakes Megalopolis the Chicago-Rochester corridor, starting at the Detroit River but continuing east beyond Lake Ontario along the St. Lawrence Seaway to Quebec City and the Gulf of St. Lawrence. Several corridors have interstate highways but no comprehensive passenger rail service. These highway routes pass through both core and fringe areas of the Great Lakes megalopolis. The upper Great lakes region has a marine corridor that connects Lakes Superior, Huron, and Michigan. However, this route does not include parallel Amtrak passenger rail or interstate highway service. I-70 follows the southern fringe of the megaregion. It runs from Kansas City MO to just
Great Lakes for Lakes Ontario and Erie were created, along with what would become the Saint Lawrence River. The Great Lakes are estimated to have been formed at the end of the last glacial period (the Wisconsin glaciation ended 10,000 to 12,000 years ago), when the Laurentide Ice Sheet receded. The retreat of the ice sheet left behind a large amount of meltwater (see Lake Algonquin, Lake Chicago, Glacial Lake Iroquois, and Champlain Sea) that filled up the basins that the glaciers had carved, thus creating the Great Lakes as we know them today. Because of the uneven nature of glacier erosion,