A sure sign of winter:

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When the Coast Guard starts Operation Taconite, their effort through out the Great Lakes to keep the shipping channels free of ice. The project started today (Monday, December 6, 2010). In an announcement made today, they said:
Initially, only one Coast Guard icebreaker will be assigned to Operation Taconite.  Coast Guard Cutter Katmai Bay, homeported in Sault Sainte Marie, has been ordered to make its way west towards Duluth, Minn., to provide ice breaking services while Coast Guard Cutter Alder is underway working aids to navigation.  Additional Coast Guard ice breakers will join the operation in the coming days and weeks.
The Katmai Bay is a 140 foot Bay-class Icebreaking Tug. In the picture above, the Katmai Bay is seen entering the Duluth Ship Canal on October 21st, 2005.

Click here for more information about the Alder