The artist Christo presented the National Gallery of Art with two original preparatory collages for 'Over The River,' both dating from 2010, for the Gallery's permanent collection. The gifts were unveiled during a press conference on November 8, 2011, with Secretary of the Interior Ken Salazar, a day after Interior's Bureau of Land Management officially approved 'Over The River,' a project for the Arkansas River in Colorado that Christo developed with his late wife and collaborator, Jeanne-Claude. The collages are on view with four earlier related works by Christo in the lobby of the East Building Auditorium through January 23, 2012.