In 1950, a plan to build a 550 foot high dam on the Green River near Echo Park threatened to forever change the character of Dinosaur National Monument, and another dam was planned downstream in Split Mountain Canyon. The dams would have inundated much of the monument's dramatic canyon scenery, submerging Fremont cultural sites, historic homesteads, spawning beds for native fish, and habitat for bighorn sheep, elk, other wildlife, and plant life. Some people supported the dams for water storage and recreation, while others defended the sanctity of national parks and the special values that made Dinosaur National Monument one of America's treasured wild places. The fight rallied a diverse coalition of citizens and organizations, including the General Federation of Women's Clubs, the American Nature Association, the Conservation Foundation, the National Parks Association, the Isaak Walton League, the Wilderness Society, and later the Sierra Club after David Brower became executive director in 1952. Brower used his publishing background to rush into print This is Dinosaur: Echo Park and Its Magic Rivers, with photographs by Martin Litton and Philip Hyde and editing by Wallace Stegner, and every member of the US Congress received a copy along with a brochure titled What is Your Stake in Dinosaur? At the same time, Howard Zahniser of the Wilderness Society negotiated with members of Congress behind the scenes. After more than five years of heated debate, President Eisenhower signed legislation for the Colorado River Storage Project on April 11, 1956, without the proposed Echo Park and Split Mountain dams, and citizens from all walks of life preserved Dinosaur's wild canyons for present and future generations.