San Andreas Lake

The lake covers 223 hectares (550 acres) in a forested valley on the peninsula south of San Francisco. The basin sits at 42 meters (138 feet) elevation and stores drinking water for nearby communities.

Spanish explorers reached the area in the late 18th century and documented the natural water source. In the late 19th century, the facility was created as a water supply for growing San Francisco.

Communities along the shore use the waterside paths for daily walks and bicycle rides through rolling terrain. School groups visit the area to learn about water management and local ecosystems.

The main path follows the eastern shore and allows walks through eucalyptus groves and grassland. The water itself is off-limits, but the route offers views across the surface.

The site lies directly on the tectonic fault that runs through California, and the dam construction accounts for underground movement. Geologists use the surroundings to study earth plates and fracture lines.

Location: California

Elevation above the sea: 138 m

GPS coordinates: 37.59320,-122.42410

Latest update: December 5, 2025 22:31