The debate over damming the Hetch Hetchy Valley in Yosemite National Park marked a crossroads in the American conservation movement. Until this debate, conservationists seemed fairly united in their aims. San Francisco's need for a reliable water supply, along with a new political dynamic at the federal level, created a division between those committed to preserving the wilderness and those more interested in efficient management of its use. While this confrontation happened nearly one hundred years ago, it contains many of the same arguments which are used today whenever preservationists and conservationists mobilize.