The Soo Locks that connect Lake Superior with the lower Great Lakes closed for the winter on January 15, 2017. This marks the end of the commercial shipping season on the lakes. Vessels are docked until it reopens on March 25. During the waiting period, they are scheduled for winter repair and maintenance.
The ships carried less cargo through the Great Lakes this year compared to volumes in 2015. They transported about 30 net tons of cargo through the Duluth-Superior harbor this year, down 4.5 percent from 2015.
Iron ore cargoes increased across the Great Lakes, as mining and steel production began to pick up again, but all other commodity shipments dropped, especially coal, which fell by more than 26 percent in 2016. With all six major taconite mines on Minnesota's Iron Range expected to be operating by March, a strong 2017 shipping season is expected.