The Mighty Soo: Construction of the Locks at Sault Ste. Marie, Michigan

When the Soo Canal was completed at Sault Ste. Marie in 1855, the journey through the rapids of the St. Mary’s river went from seven weeks of arduous portaging to seven minutes through the newly constructed State Locks.1 Over the next century, four locks would be constructed, repaired, and replaced, leading to more tons of freight passing through the Soo Locks in the mid-20th century than the Panama, Suez, and Manchester canals combined.2

Fourteen men pose for a group photograph while standing on a dike in the Hay Lake Channel. A label on the original photograph reads "October 27, 1889. Middle Neebish, Hay Lake Channel. Dike from Lower End."
77-SOO-U-49: Middle Neebish, Hay Lake Channel: Men Assembled On Dike, Viewed From Lower End, October 27, 1889.

Last summer, the Still Picture Branch accessioned a collection of glass plate negatives and digital surrogates from the U.S. Army Corps of Engineers (USACE) Soo Area Office. This series of over 1,700 plates documents the construction and ongoing improvement of three of the U.S. federal locks of the Soo Canal (the Poe, Davis, and Sabin locks), as well as improvements and repair conducted on the first federal lock, the Weitzel. Additional subjects include U.S. Lake Survey expeditions, shipwreck of the steamer Susan E. Peck, views of the old State Locks, the widening and deepening of the West Neebish Channel, and diagrams from a 1925 paper by L. C. Sabin for the Marine Review.

Men working down in an excavation site, their equipment precariously supported by two by four planks of wood. One man observes the workers from a shelf halfway down the excavation, while the legs of people standing some twenty feet above at the top of the image. Label on the original photograph reads, "August 17, 1893. Excavation for bulkhead between locks, looking south."
77-SOO-166: Between Locks: Excavation For Bulkhead Looking South, August 17, 1893.

Most of the original photographs are gelatin dry plates, which were the first photographic negative materials to be manufactured and mass produced and saw peak usage from 1880 to 1925.3 Because of the fragile nature of the glass support, some deterioration such as cracking and emulsion flaking is nearly unavoidable after a century of varying storage conditions; however, a majority of the plates included in this collection are intact, and all have been scanned by staff from the Clarke Historical Library at Central Michigan University in conjunction with USACE. It is thanks to their efforts that this collection will soon be available to view in the National Archives Catalog, allowing us to provide access to these photographs while also preserving the originals. For more information about the scanning project, please see this article.

This series will soon be described in the National Archives Catalog, where the digital image files will also be made available later this year. Reference queries regarding images in this collection may be sent to

UPDATE: These images are now available to view and download from the Catalog.

Fun facts about the Soo Locks:

  • In the 17th century, the word sault – an archaic spelling of the modern French word saut meaning “jump” – was applied to cataracts, waterfalls and rapids.
  • While the city name retains the old French spelling, Soo is the usual anglicized spelling when writing about the locks; both, however, take the anglophone pronunciation “soo”. (Across the river in Canada, the city is also called Sault Ste. Marie, but takes the francophone pronunciation “soh”.)
  • During the Civil War, the Soo Canal and its locks facilitated the southward transport of hundreds of thousands of tons of iron ore from mines in Lake Superior country, supplying the Union war effort with much needed raw material for weapons manufacture.
  • In 1883, some 4,000 vessels carrying 1.8 million tons of freight passed through the canal locks at Sault Ste. Marie. In 1893, 12,000 vessels carried over 10 million tons of freight through, using only the Weitzel Lock.4
  • By 1948, after the Weitzel Lock was replaced by the much larger MacArthur Lock and with the three additional locks, annual freight tonnage peaked at 217 million tons.4
  • To this day, the locks close for 10 weeks during the winter months , which is the only time major repairs and improvements can take place.

Works Cited

  1. Arthur M. Woodford. Charting the Inland Seas: A History of the U.S. Lake Survey. U.S. Army Corps of Engineers, Detroit District. 1991.
  2. Michigan Historical Commission. The History of Great Lakes Transportation. Manual to accompany filmstrip. Prepared by Philip P. Mason for the Michigan Historical Commission through the Munson History Fund. Lansing, July 1957.
  3. Graphics Atlas. Image Permanence Institute, Rochester Institute of Technology.
  4. John W. Larson. History of Great Lakes Navigation. National Waterways Study, U.S. Army Engineer Water Resources Support Center, Institute for Water Resources, 1983.

Related Records

2 thoughts on “The Mighty Soo: Construction of the Locks at Sault Ste. Marie, Michigan

  1. Thank you very much for this blog post. We tend to take engineering marvels like this for granted, and to have the photographic record is wonderful. As a family and local historian, I know that the Soo Locks are an unsung but important part of the settlement and development of the Great Lakes area. A fun boat trip, too!

Comments are closed.