The Tuolumne River supplies 85% of the water for 2.4 million people. It originates from pristine spring snowmelt as far upstream as Mt. Lyell at an elevation of 13,114 feet.

The City and County of San Francisco protects the resources entrusted to its care by continuously monitoring this watershed and working with the park to minimize pollution.

Natural occurrences such as fire and erosion can affect water quality. More than 1,000 water samples are taken annually to protect the water quality of the Hetch Hetchy System.

(caption) The Tuolumne River flows gracefully through Yosemite National Park.

(caption) Water quality specialists take samples from the river in Tuolumne Meadows to test for microorganisms.

(inset) What is Watershed? A watershed is an area that is delineated by high ridges such as cliffs, hills and mountains. Rain or snowmelt flows down from the ridges and collects in streams, rivers and other water bodies, such as lakes and reservoirs. Watershed protection is a top priority because it affects the quality of water for people downstream and everything that lives within these boundaries.

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Show me all markers in:  Groveland, CA  |  Tuolumne County  |  95321  |  California  |  United States of America

Hetch Hetchy Reservoir and O'Shaughnessy Dam
Producing Clean Renewable Energy
Trails and Waterfalls
Hetch Hetchy Railroad
O'Shaughnessy Dam
A Storied Landscape
Waterfalls of Yosemite Valley
The Journey to Yosemite
In Memory of David Erickson
Big Gap Flume

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