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Imagining "Over the River"This gallery is part of a special National Geographic News series on global water issues.
Artist Christo, sitting next to wife Jeanne-Claude, describes his planned art exhibition "Over the River, A Work in Progress" at a press conference in Lausanne, Switzerland, in February 2009. Jeanne-Claude died later that year. The outdoor art installation would involve suspending translucent, wind-rippled fabric panels, along a 40-mile (62-kilometer) stretch of the Arkansas River in Colorado. The panels would total 5.9 miles (9.4 kilometers), according to Christo's website. The massive work—if approved by the U.S. Bureau of Land Management this spring—will take more than two years to construct and will be shown for two weeks in the summer of 2014. (Check out National Geographic's freshwater 101 page.) Christo—a U.S. artist known by a single name—is well known for creating large-scale works of art that incorporate the environment, such as "The Gates" in New York City's Central Park in 2005. —Ker Than

Photograph by Dominic Favre, Keystone/AP