Sault Sainte Marie Canals

Sault Sainte Marie Canals, also Soo Locks, three canals, east central North America, two in northeastern Michigan and one in southern Ontario. The canals, all toll-free, are in the Saint Marys River, which connects Lake Superior and Lake Huron. On opposite banks of the river are Sault Sainte Marie, Michigan, and Sault Ste. Marie, Ontario.

The U.S. waterways, also called the Saint Marys Falls Canals, have four parallel locks and are each 2.3 km (1.4 mi) long. The North Canal includes Davis lock (opened 1914) and Sabin lock (1919), and the South Canal includes MacArthur lock (1943) and Poe lock (1969). The Canadian canal, 2.1 km (1.3 mi) long, has one lock (1895). These canals allow ships to navigate a section of the St. Marys River made hazardous by a 1.2-km (0.75-mi) stretch of rapids and a substantial drop in the level of the river (as much as 6.4 m/21 ft) 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 U.S. 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 U.S. 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 U.S. waterways.