The Minneapolis skyline rises in the background as Chase Hazen of Discovery Bay, Calif., practices in the surf division during the World Wakesurfing Championships on the Mississippi River as part of the Aquatennial Festival. Wakesurfers start with the aid of a tow rope, then release and surf a boat's wake.
Environmental Protection Agency contractor Andy Kallus collects water samples for testing near the point where the south pass of the Mississippi River meets the Gulf of Mexico near Venice, La. The long-term effects of the Deepwater Horizon oil spill are still being investigated for the impact they will have on the fragile ecosystem of the Gulf Coast.
EPA contractors Larry Howard, left, and Andy Kallus, right, collect water samples for oxygenation levels and other tests near where the Mississippi River meets the Gulf of Mexico near Venice, La., as boat captain Jacques Blaize maneuvers.
An oil-covered crab is seen on an oil-impacted beach at the mouth of the Mississippi River near Venice, La. Experts fear the worst for the wildlife along the Gulf Coast.
Greenpeace worker Lindsey Allen collects samples of oil that washed up along the mouth of the Mississippi River near Venice, La.
Ribbons of oil float on the Gulf of Mexico on Tuesday near the mouth of the Mississippi River south of Venice, La. An oil slick originating from the Deepwater Horizon oil rig explosion site in the Gulf of Mexico has started drifting ashore along the Louisiana coast.
Greenpeace marine biologist Paul Horsman shows oil collected from a jetty at the mouth of the Mississippi River near Venice, La.
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The Mark Twain Riverboat ferries tourists along the Mississippi River. The narrated tours and dinner cruises offer a different perspective of Hannibal, Mo.
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Visitors to Cardiff Hill get a bird's-eye view of the Mississippi River below.
Oil is seen on the starboard side of the Mississippi Responder oil skimmer ship, which is docked near the South Pass of the Mississippi River on the Louisiana coast.
Jordan Ellis shows oil scooped up from the Gulf of Mexico, 17 miles southeast of the South Pass of the Mississippi River.
A fisherman motors through heavy fog Wednesday on the Mississippi River near East Dubuque, Il.
A fisherman stands near his boat on the main channel of the Mississippi River as ice begins to break apart from warmer temperatures near Dubuque, Iowa.
The shimmering Gateway Arch on the banks of the Mississippi River is St. Louis' calling card. But the iconic monument set off from the rest of the city is, well, set off from the rest of the city.
The USS New York sails down the Mississippi River through the Port of New Orleans. The ship was built with about 8 tons of steel from the World Trade Center site and is on its way to New York, its home port.
Workers look at part of a sunken oil barge that shifted, spilling crude oil into the Mississippi River near the Crescent City Connection in New Orleans. A ship collided with an oil barge last week causing a large oil spill that briefly shut down commercial traffic on the river.
Coast Guard personnel work to contain a fuel oil spill in the Mississippi River at the Port of New Orleans. The Coast Guard closed a section of the river after a tugboat pushing a barge and a 600-foot tanker collided. The fuel oil barge carried fuel oil and had a capacity of 10,000 barrels.
Even as some waterlogged Midwestern tourist spots mop up from this month's deluges, others are bracing for damage from a rain-swollen Mississippi River.
Sarah Grimmett watches from the second floor of her apartment complex as the swollen Mississippi River flows behind a wall of sandbags in Clarksville, Mo.
The Mississippi River gushes through a break in an Indian Grave Drainage District levee north of Quincy, Ill.
A National Transportation Safety Board investigator examines a portion of the Interstate 35W bridge in Minneapolis, which collapsed over the Mississippi River on Wednesday.
Wrecked cars are mixed in with debris from the Interstate 35W bridge over the Mississippi River in Minneapolis after it collapsed during the evening rush hour Wednesday. The eight-lane bridge was undergoing repair work when it broke apart during rush hour, sending at least 50 vehicles into the river.