SAULT STE. MARIE, Mich. -- The Soo Locks in Sault Ste. Marie, Michigan will close to all marine traffic beginning 11:59 p.m. January 15, or until commercial traffic ceases, through 12:01 a.m. March 25 to perform seasonal critical maintenance.
Federal regulation (33 CFR 207.440) establishes the operating season based on the feasibility of vessels operating during typical Great Lakes ice conditions.
“Every year, our lock and dam operators transition from assisting vessels through the Soo Locks to performing maintenance on the locks,” Operations Branch Chief Jeff Harrington said. “The team works alongside Soo Project Office maintenance crews to provide 100% effort in completing all critical maintenance during the ten-week shutdown. They work long hours in harsh northern Michigan winter conditions to complete a significant amount of maintenance during this annual closure period.”
This winter maintenance period, the MacArthur Lock will not be dewatered and will close for the season when the weather or ice conditions make operation unsafe and/or inefficient, or when the Poe Lock closes, whichever comes first. Communication with industry will be made at least 48 hours prior to closure. The MacArthur Lock is scheduled to reopen in late April 2026.
The Poe lock will remain operational (on a 24-hour basis) through January 15, 2026, or until commercial traffic ceases - whichever occurs first. The Poe Lock will be dewatered during the maintenance season and is scheduled to reopen on March 25.
The team will install temporary panel bridges across the MacArthur and Poe Lock. The panel bridges will provide the ability to mobilize materials and equipment to the job sites throughout the winter closure.
Maintenance on the MacArthur Lock will include the Soo Project Office fabricating and replacing spring boxes and lever arms for Gates 3, 4 and 5, constructing a recess cutout for the panel bridge, repairing a Gate 2 strut arm, as well as concrete and deck plate repairs to Gate 5
Maintenance on the Poe Lock will include underfloor cleanout and manhole inspection, a five-year periodic assessment, Gate 1 repairs, Gate 4 lifting lug installation, Gate 3 jacking pedestal repairs and testing of Ice Study wall coating.
In addition to the above, crews will also perform a wide range of other maintenance tasks from the replacement of pier fender timbers to inspections and preventative maintenance on electrical and mechanical systems on both the Poe and MacArthur Locks.
“Reliable Great Lakes navigation and the momentum of the American manufacturing supply chain depend on getting the job done here. In an unforgiving northern climate, our exceptional team tackles the complex maintenance demands of aging infrastructure, proving their skill on systems well past their service life.” Soo Locks Operations Manager LeighAnn Ryckeghem said.
More than 4,500 vessels, carrying up to 80 million tons of cargo, maneuver through the locks annually. Iron ore, coal, wheat and limestone are among the most frequently carried commodities. Opened in 1969, the Poe Lock is 1,200 feet long. The MacArthur Lock opened in 1943 and is 800 feet long.
The U.S. Army Corps of Engineers, Detroit District, maintains a navigation system of 81 harbors, including the Great Lakes Connecting Channels that join lakes Superior, Michigan, Huron, St. Clair and Erie.
Visit the Detroit District Facebook page https://www.facebook.com/USACEDetroitDistrict for information about the last vessel to transit the Soo Locks for the 2025-2026 shipping season and updates on maintenance work.
-30-