The Soo Locks consist of two canals and four locks: Davis Lock, Poe Lock, MacArthur Lock, and the Sabin Lock (closed), that allow vessels of many types and sizes to safely traverse the 21-foot drop in elevation of the St. Marys River between Lake Superior and Lakes Michigan and Huron.<br> The St. Marys River, 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. This natural barrier to vessel navigation made necessary the construction of the locks project known as the St. Marys Fall Ship Canal.<br> Long ago the Ojibway (Chippewa) Indians, who lived in the area, would carry their canoes around the rapids to reach Lake Superior from the St. Marys River.<br> As European pioneers arrived creating larger settlements with increased trading the need for larger boats grew. It became necessary to unload the boats, haul the cargo around the rapids in wagons, and then reload alternate boats on the other side. This process took valuable time. The need to build a lock became apparent thus the world-famous Soo Locks were built to form a passage around the rapids in the river.<br> In the late 1700s a Canadian company built a lock on the Canadian side of the river. It 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 and then designated the State Locks. Although the state charged a lockage toll, commerce grew and the locks became important on a national level.<br> 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 Fall Canal.<br> In the early days lock gates were opened manually. Now the gates are opened with the push of a button. The Corps is currently planning to automate the hydropower plan bringing that facility up to 21st Century technology also.<br> The Corps has plans to replace the Davis and Sabin Locks with a larger state-of-the-art lock, similar to the Poe Lock, to assist in handling the larger vessels of the Great Lakes fleet. The new lock will be the first lock built at the Soo since 1968. The Corps is looking forward to building this project and bringing this technologically advanced facility to the people of the United States.