Sault Ste Marie Exercise U.S. Coast Guard photograph

SAULT STE. MARIE, Mich. - An oil-spill responder with Marine Pollution Control positions containment boom in the St. Mary's River in Sault Ste. Marie, Mich., during an oil-spill response exercise there Sept. 14, 2011. The exercise - involving about 270 participants from Canadian, federal, tribal, state and local agencies - was based on a scenario involving a collision between two vessels, resulting in roughly 220,000 gallons of oil spilling into the river. (U.S. Coast Guard photo by Coast Guard Auxiliarist Dock Borth)