Great Lakes Circle Tour through the province, running the entire length from the Peace Bridge to the Ambassador Bridge. Unlike the other four Great Lakes, Lake Ontario is posted not as a circle tour but as part of the US-only Seaway Trail. The trail begins in Erie County, Pennsylvania and travels through Buffalo, Niagara Falls, Rochester, Oswego, and Ogdensburg before ending at the Seaway International Bridge near Massena. Plans for the Great Lakes Circle Tours were started in 1985. The Michigan Department of Transportation (MDOT) was in consultation with its counterparts in Wisconsin (WisDOT), Minnesota (MnDOT) and Ontario (Ministry of Transportation of Ontario, MTO)
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,