Affectionately called the “Linchpin of the Great Lakes” by the United States Army Corps of Engineers, the Soo Locks are an engineering marvel with roots dating back to the mid-1800s. The locks are located on the St. Marys River between Lake Superior and Lake Huron. There is a 21-foot difference between the levels of the two lakes. The locks allow freighters, barges, tugboats, and other water vessels to be raised and lowered to travel along the St Mary’s River. Thanks to the Soo Locks, freighters over 1,000 feet in length can travel freely along the river all the way from Duluth, Minnesota, outward into the Atlantic Ocean and beyond.

Roughly 7,000 vessels pass through the Soo Locks every year, hauling nearly 86 million tons of cargo. An estimated 500,000 people visit the locks each year to watch the process. You can watch from the observation platform or by going on a Soo Locks boat tour. Two of the four locks are still used by public ships. Most utilize the Poe Lock (1,200 feet), which was rebuilt in 1968 to accommodate larger and more modern ships. Also still in operation, the MacArthur Lock (800 feet) was constructed in 1943 to replace the Weitzel Lock, which had been built in 1881. Named after General Douglas MacArthur, it is the lock closest to Sault Ste. Marie and can be seen from the observation deck in the Soo Locks Park. The Davis and Sabin Locks were built in 1914 and 1919, respectively. Currently, only Soo Area Office vessels use the Davis, while the Sabin was officially decommissioned in 2010 after being inactive since 1989.