Sign Of Spring: Lake Superior’s 2025 Shipping Season About To Get Underway

Shipping traffic in the Duluth Harbor is about to ramp up for the 2025 season as the Soo Locks prepare to open after a winter shutdown.

Ships coming in under Duluth's Aerial Lift Bridge and the Superior Entry to the Duluth/Superior Harbor are not only a major part of the region's industry, but also a welcome sign of springtime for shipwatchers and residents of the Twin Ports area.

The US Army Corps of Engineers announced on March 13 that they are preparing to open this major gateway on the Great Lakes in a matter of days, signaling a start to this year's shipping season.

Why were the Soo Locks shut down?

It is common practice for the locks to be closed down for a period of time during the winter months for repairs and maintenance.

The locks are a critical link that allows traffic between Lake Superior to the rest of the Great Lakes for shipping traffic, creating a navigable path for ship traffic on St. Mary's River between Lake Superior and Lake Huron.

The Corps of Engineers shut the locks down for the season on January 16, 2025, for maintenance and repairs during the winter off-season. The $2.7 million project focused on the Poe Lock and upstream work, although there is also ongoing maintenance on the MacArthur Lock during the offseason.

When do the locks open?

The MacArthur Lock will remain closed until April, but the Poe Lock will be opened to shipping traffic starting on Friday, March 21 at 8:00 am.

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This is an earlier-than-anticipated opening, with work on and around the Poe Lock getting done earlier than initially expected.

This opening is a day before the Montreal/Lake Ontario sections of the St. Lawrence Seaway and the Welland Canal open (on March 22) marking the full opening of the 2025 Great Lakes shipping season.