One is the drainage area of the Merced River. The Merced River flows through the southern portion of the park and passes through the famous Yosemite Valley. The other drainage area is north of Yosemite Valley, about a day's journey by horse. This drainage area contains the Hetch Hetchy Valley and the Tuolumne River. This is an area where nobody could live.
People can travel there only three or four months during the summer.
In other months the roads and trails are covered with snow and ice. Since the valley is in a national park, permission to build a dam must be given by the Federal Government. The committee on the Public Lands of the House of Representatives will decide whether or not the people of San Francisco can build a dam across the Tuolumne River. If the dam is built, the Hetch Hetchy Valley will be flooded and access to its natural resource will be lost. In this activity you will be exploring water issues in California since 1900.