Sault Sainte Marie Canals

Sault Sainte Marie Canals, also Soo Locks, three canals, east central North America, two in north-eastern Michigan, United States, and one in southern Ontario, Canada. The canals, all toll-free, are in the St Marys River, which connects Lake Superior and Lake Huron. The United States and Canadian canals are on opposite sides of the river and are alternative routes between the lakes. The US canals have a total of four locks, and the Canadian canal one lock, to accommodate both a 1.2 km (0.75 mi) stretch of rapids on the St Marys River and the 6.4 m (21 ft) drop from the elevation of Lake Superior to that of Lake Huron.

The great bulk of the cargo carried through these busy canals, which are closed by ice from January to April, is east bound. Most of this cargo is iron ore and grain. The chief goods shipped west are coal and petroleum. Since the structural failure of the Canadian lock in 1987, all freight is shipped via the US facilities.

The first canal in the St Marys River was opened on the Canadian side in 1798. It was destroyed during the War of 1812. After 1839, ships were moved around the rapids on rollers. In 1895, Canada completed its existing canal. A US canal was completed by the state of Michigan in 1855. It was taken over in 1881 by the federal government and formed the basis for the present US waterways.