Jump to: Preparation Procedure Evaluation 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 c