In this Monday, March 23, 2015 photo, National Park Service Director Jonathan Jarvis, left, and the head of the National Park Foundation Dan Wenk stand in an empty Lincoln Memorial Reflecting Pool on ... more 
In this Monday, March 23, 2015 photo, National Park Service Director Jonathan Jarvis, left, and the head of the National Park Foundation Dan Wenk stand in an empty Lincoln Memorial Reflecting Pool on the National Mall in Washington. With its centennial approaching in 2016, the park service will launch a major campaign Thursday, April 2 in New York City to raise support and introduce a new, more diverse generation of millennials and children to "America's best idea," the national parks. (AP Photo/Pablo Martinez Monsivais) less 
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Associated Press | Photo By Pablo Martinez Monsivais
Mon, Mar 30, 2015 5:18 AM EDT