The U.S. Army Corps of Engineers says the Soo Locks in Sault Ste. Marie in Michigan's Upper Peninsula have opened for the 2013 Great Lakes shipping season.

Soo lockmaster Bill Campbell said Monday that the Paul R. Tregurtha was the first ship to enter the Poe Lock at 12:01 a.m. headed from Sturgeon Bay, Wis., to Duluth, Minn.

Six vessels had passed through the Poe Lock by 9 a.m. Monday.

The locks were closed on Jan. 15 and underwent routine repairs and maintenance during the winter shutdown. The MacArthur Lock beside the Poe Lock will continue maintenance for several weeks.

Freighters hauling coal, iron ore, grain and other materials pass through the locks each year.

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