DULUTH, Minn. — The Soo Locks’ seasonal closure Jan. 15, 2026, capped a challenging 301-day navigation season for the Port of Duluth-Superior.
Hampered by a combination of unfavorable market trends and geopolitical forces, total waterborne tonnage at North America’s farthest-inland seaport fell to 25.3 million short tons for the 2025 season—a 14.6% decline from 2024 and 16% below the five-season average.
Bulk cargo movement slowed the most, with iron ore, limestone, grain, coal, cement and salt all declining against the five-season average. By tonnage, iron ore fell furthest, sinking from 19.4 million tons in 2024 to 16.5 million tons in 2025. A 2.5 million-ton reduction in iron ore exports to Canada comprised the majority of that decline. Domestic iron ore shipments fell 530,000 tons, or 3.9%.
Across all cargo categories, total Canadian trade dropped 41% compared to 2024. Overseas trade fell 30% to its lowest level since before the St. Lawrence Seaway opened in 1959. Grain tonnage dropped to its lowest level since 1890.
“Anything that affects global trade affects our port,” said Kevin Beardsley, executive director of the Duluth Seaway Port Authority. “It’s a challenging environment, particularly for U.S. Great Lakes ports.”
Breakbulk cargo provided the lone highlight in 2025, narrowly exceeding 2024 volumes. Much of that was manufacturing, mining and energy sector cargo moving through Duluth’s Clure Public Marine Terminal.
The 2025 season was a Seaway-era low for oceangoing arrivals (44) in Duluth-Superior, but nearly half of those ships called at the Clure Terminal with heavy-lift/project cargo for Duluth Cargo Connect.
“It’s a testament to the advantages we offer for the high, wide and heavy cargoes moving to or from the midsection of North America,” said Beardsley. “In terms of geography, infrastructure and personalized service, Duluth Cargo Connect is the best fit.”
Winter layup
With the season now complete, six active vessels are wintering in the port, each at docks in Superior, Wisconsin. Skilled tradespeople will perform millions of dollars in maintenance and improvements to those vessels over the next eight weeks, readying them for the Soo Locks’ scheduled opening on March 25, 2026.
| Vessel | Dock |
| Burns Harbor | Redwood Group Elevator M |
| Honorable James L. Oberstar | Fraser Shipyards |
| Indiana Harbor | Ogdensburg Pier |
| John J. Boland | Fraser Shipyards |
| Lee A. Tregurtha | Fraser Shipyards |
| Mesabi Miner | Fraser Shipyards |
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The Port of Duluth-Superior is North America’s farthest-inland seaport and the Great Lakes’ all-time tonnage leader. A multimodal cargo gateway for global trade, it connects midcontinent markets via the Great Lakes-St. Lawrence Seaway System, direct Class I rail and free-flowing highways. The port is a catalyst for regional economic development, sustaining more than 7,000 jobs and generating $1.6 billion in annual economic activity. Learn more at DuluthPort.com.