In August 1992, 1993 and 1994, in search of a site for the project, Christo and Jeanne-Claude and their team traveled 14,000 miles (22,530 kilometers) in the Rocky Mountains in the United States. On those trips, the team prospected eighty-nine rivers, in seven states, and six possible locations were found. After visiting the six sites again in the summer of 1996, the Arkansas River in Colorado was selected.
Christo received all federal, state and local permits necessary to realize Over The River in 2011, when the US Department of the Interior announced its Record of Decision. This federal action was the final step of an Environmental Impact Statement (EIS), which is usually reserved for major infrastructures such as bridges, highways, dams and airports. The EIS for Over The River, the first ever completed for a work of art, began in the spring of 2009 and was prepared by the Bureau of Land Management, Royal Gorge Field Office, resulting in a 1,686 page comprehensive analysis.
In 2012, a local group opposed to this temporary work of art filed lawsuits against Colorado State Parks in State Court and against the United States Federal Government, Bureau of Land Management, in U.S. Federal Court. In January 2017, after pursuing Over The River, Project for the Arkansas River, State of Colorado for 20 years and going through five years of legal arguments, Christo decided to no longer wait on the outcome and devote all of his energy, time and resources into the realization of The Mastaba, Project for Abu Dhabi, United Arab Emirates.
For more info: http://christojeanneclaude.net/projects/over-the-river