Saint Marys Falls Ship Canal (Soo Locks Historic District, Soo Canals)

A bird's eye view of the Saint Mary's Lock canal system


The Soo Locks Historic District is historically significant for many reasons. The property is important for its contribution to the industry and commerce of the United States by providing an inexpensive and convenient transportation route to and from the upper Great Lakes. The locks are also significant engineering feats, having required much time, organization, and capital investment to design and operate them. Several buildings on the locks property possess architectural significance for their continuity and elegance in design, as well as being the work of master architects. The history of hydroelectric power in the Soo Locks Historic District is also significant, as it is the site of a very early hydroelectric plant. The locks have also been an important tourist and recreational site since the first locks of 1855.


  • 1959, State Register of Historic Sites
  • 1966, National Historic Landmark
  • 1966, National Register of Historic Places


  • Smith, Hinchman and Grylls, architects
  • Edward Pearce Casey, designer
  • United States Army Corps of Engineers, designers


  • 1668, Jacques Marquette and Louis de Boesme reoccupy a mission site (first established in 1641) below the rapids at the Sault
  • 1853, ground was broken on June 4 for construction of the locks at Sault Ste. Marie
  • 1855, the first locks (the State Lock) opened, June 18
  • 1881, the Secretary of War assumed possession of the locks on June 9; The Weitzel Lock opened, September 1
  • 1896, the original Poe Lock opened, August 3
  • 1897, the Administration Building, designed by Edward Pearce Casey, was completed. It served as the canal office and Poe Lock pumphouse
  • 1914, the Davis Lock opened, October 21
  • 1919, the Sabin Lock opened, September 18
  • 1942, construction began April 20 on the MacArthur Lock, constructed on the site of the old Weitzel Lock
  • 1943, the MacArthur Lock opened, July 11, after 14 months of around-the-clock construction
  • 1964, construction for a new Poe Lock (on the site of the original Poe Lock) began again on August 7 after a delay for redesigning purposes
  • 1969, the new Poe Lock opened, June 26