Lake Superior ice cover in the vicinity of Ontonagon, Michigan on February 28, 2003. Photos taken by Jill Ladwig, Editor, Univ. of Wisconsin Aquatic Sciences Center.

Grand Marais Observation Platform, Lake Superior. February 13, 2008. Photo from NWS Marquette, MI.

Grand Marais Observation Platform, Lake Superior. February 13, 2008. Photo from NWS Marquette, MI.

Ice formation on Lake Michigan, St. Joseph area. 1998. GLERL, M. McCormick.

Ice formation on Lake Michigan, St. Joseph area. 1998. GLERL, M. McCormick.

Ice core sampling in Green Bay, Lake Michigan. February 26, 2002, G. Leshkevich, GLERL.

MV Saginaw was the last ship to traverse the Soo Lock in Sault Ste. Marie, MI, Thurs. January 15, 2009, marking the lock's closure and the end of the Soo Lock's shipping season. U.S. Army Corps of Engineers.

MODIS satellite image of the Great Lakes showing maximum ice extent. March 4, 2009.