<p>SAULT SAINTE MARIE, Mich. - After spending the summer working in the St. Marys River, the tugboats Bill Maier, Hammond Bay and Derrickbarge H.J. Schwarz enter the Poe Lock to begin their long journey home to Duluth. It will take the tugs and string of barges about four days to cross Lake Superior if the weather holds.
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(U.S. Army Corps of Engineers photo by Michelle Hill)
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/41937383@N07">U.S. Army Corps of Engineers Detroit District</a>
<p><a rel="nofollow" class="external text" href="https://www.flickr.com/photos/detroit_district/8023971781/">Bringing up the Rear</a>
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