 In 1903, a dam in the northern portion of the park was proposed. Located in the Hetch Hetchy Valley, its purpose was to provide water and hydroelectric power to San Francisco. Muir and the Sierra Club opposed the project, while others, including Gifford Pinchot, supported it. In 1913, the U.S. Congress authorized the O 'Shaughnessy Dam through passage of the Raker Act.
