The Great Lakes-St. Lawrence Seaway System is a vital link in the shipping and navigation operation throughout the continent and the world.

Corps responsibility in the Great Lakes dates back to the 1840's, with the opening of harbors and the building of lighthouses necessary for safe navigation.

Since then, our responsibility has grown to include the maintenance of commercial harbors and shipping channels throughout the Lakes. This job has been made easier and more efficient in recent years with the advent of vessels with electronic survey systems. These vessels electronically "sweep" the channel bottom, giving the crew a cross-section computer printout of the area. If an obstruction is located, dredging operations are carried out to clear the obstruction from the navigation channel.

Since the opening of the St. Lawrence Seaway in 1959, the Detroit District has initiated improvement in the Great Lakes to accomodate ocean going vessels, not only to open up the Great Lakes for world shipping, but also to take advantage of increased interlake shipping.

Since 1881, we have operated and maintained the Soo Locks at Sault Ste. Marie, Michigan, which allow vessels to safely traverse the 23 foot drop in water level between Lake Superior and Lake Huron.

Between 12,000 and 15,000 vessels pass through the Soo Locks each year, carrying more tonnage than any other set of locks in the world. The largest of four locks, the Poe, measures 1200 feet in length and 110 feet wide and can handle the largest vessels traversing the Great Lakes today.

Visitors can observe the locking process from an oservation platform maintained by the Corps, and learn the history and role of the locks through displays at the Corps' visitors center.

Other Corps facilities located on the St. Marys River at Sault Ste. Marie, Michigan, include a hydroelectric power plant and the Lake Superior Compensating Works Structure which is jointly controlled by the United States and Canada.