Marie rapids into Lake Huron and find a huge backwater in Lake Michigan.[9] Out of Lake Huron again they flow past Detroit into Lake Erie.

From Duluth, at the westernmost extremity of Lake Superior, to Buffalo, on the easternmost point of Lake Erie, including all Lake Michigan and Lake Huron, with its bays and channels, a steamer can pass with just the one difficulty (easily surmounted) of the rapids at Sault Ste.

Marie between Lake Superior and Lake Huron.

But after you have left Lake Erie on the east you find yourself in the Niagara River, which at the Niagara Falls plunges several hundred feet downwards into Lake Ontario.

From Lake Ontario to the sea along the St.Lawrence there is uninterrupted navigation, though there are rapids that require careful steering both with steamers and boats.