The name Sault Ste Marie is a combination of the French word, "Sault," meaning rapids of falls, and the name of "Sainte Marie," the patron saint of the first Jesuit missionaries who visited the area. Over the years, passing sailors have anglicized this to "Soo," a popular nickname which has given the region world wide recognition. The St. Marys River is the only water connection between Lake Superior and the other Great Lakes. Known as the St. Marys Rapids, falls about 21 feet from the level of Lake Superior to the level of the lower lakes. The natural barrier to vessel navigation made necessary the construction of the locks project known as the St. Marys Falls Ship Canal. In the late 1700's a Canadian company built a lock on the Canadian side of the river that was destroyed in the War of 1812. A private American company built locks on the U.S. side of the river in 1853. These locks were turned over to the State of Michigan in 1855. In 1881 the locks were transferred to the U.S. government giving jurisdiction to the U.S. Army Corps of Engineers. Currently, the Corps operates the locks toll free to any vessel wishing to pass through the St. Marys Falls Canal. More than 11,000 vessels, carrying up to 90 million tons of cargo pass through these locks every year. Vessels varying in size from small passenger vessels and workboats to large 1,000 foot ships carrying more than 72,000 tons of freight in a single load. The channels are maintained at a draft of 25.5 feet at low water datum. The lock system is inspected for structural soundness during the winter when lock operations close.