The Coast Guard said operation Taconite ended Thursday and encompassed all of Lakes Superior and Michigan, the northern half of Lake Huron, the St. Marys River, and the Straits of Mackinac between Michigan's upper and lower peninsulas.
Coast Guard Sector Sault Ste. Marie ran the 160-day operation, which included more than 5,000 hours of ice breaking for convoys. Nearly 950 commercial ships were assisted.
The Coast Guard said the past winter season is believed to have produced the thickest and most expansive ice cover on the Great Lakes in the past 35 years.