Photos show how FDR's 'tree army' helped shape America's national parks — and how the NPS has changed since

Members of the Civilian Conservation Corps (CCC) at a camp in Oregon. CORBIS/Corbis via Getty Images The National Park Service, created by President Woodrow Wilson, turned 110 years old on August 25. Its 12,600 full-time employees oversee 85 million acres and manage a multibillion-dollar budget. Recent cuts have threatened the agency's ability to maintain its operations and visitor levels. Before federal rangers became stewards of America's 63 national parks, responsibility was fragmented…