Great Lakes passenger steamers Lakes) and a high-speed catamaran running between Milwaukee, Wisconsin and Muskegon, Michigan. An international ferry ran on Lake Ontario from Rochester, New York to Toronto from 2004 to 2005, but it was plagued with high operating costs and low demand. The privately owned company was taken over by the City of Rochester, and the ship was sold overseas where it operated across the Strait of Gibraltar. Cruise ship traffic on the Great Lakes increased in the early-21st century, with ships like the MS Hamburg, the MS Saint Laurent and the smaller ships of the Great Lakes Cruise Company offering multi-day
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,