The National Wildlife Refuge System grew through a series of milestones beginning in 1903 with the establishment of Pelican Island in Florida, followed by the Wichita Mountains Forest and Game Preserve in 1905, the National Bison Range in Montana in 1908, and the National Elk Refuge in Wyoming in 1912. Congress passed the Migratory Bird Treaty Act in 1918, and in 1933 the Civilian Conservation Corps provided labor for many refuge projects. In 1934, Franklin D. Roosevelt convened a committee to save waterfowl, and Aldo Leopold, J.N. Darling, and Thomas Beck suggested the duck stamp, after which Congress passed the Duck Stamp Act. In 1935-36, J.N. "Ding" Darling, head of the U.S. Biological Survey, sent J. Clark Salyer to purchase prime wetlands nationwide. In 1940, service scientist Rachel Carson wrote the Conservation in Action series. The Fish and Wildlife Act in 1956 broadened authority for the acquisition and development of refuges, and in 1958 Congress amended the Duck Stamp Act to authorize the Waterfowl Production Area program. The Arctic National Wildlife Range was established by the Eisenhower Administration in 1960, followed by the Refuge Recreation Act in 1962, the Wilderness Act in 1964, and the National Wildlife Refuge System Administration Act in 1966. Later milestones included the Endangered Species Act in 1973, the Bicentennial Land Heritage Program in 1976, the Alaska National Interest Lands Conservation Act in 1980, the establishment of the five hundredth National Wildlife Refuge at Canaan Valley in West Virginia in 1994, the National Wildlife Refuge System Improvement Act in 1997, the Volunteer and Community Partnership Enhancement Act in 1998, the National Wildlife Refuge System Centennial Act in 2000, and a century of conservation celebrated in 2003.