Mammoth Pool Reservoir

Mammoth Pool Reservoir is a large man-made lake in the Sierra Nevada Mountains, fed by the San Joaquin River and created by an earth-fill dam completed in 1960. The water stretches roughly 5 miles long and half a mile wide, with clear cold water surrounded by steep forested hillsides that rise directly from the shoreline.

The reservoir was created in 1960 when Mammoth Pool Dam was completed as an earth-fill structure operated by Southern California Edison. It forms part of the Big Creek Hydroelectric Project, one of the world's largest hydroelectric systems that generates nearly 200 megawatts of power to supply electricity to homes across the region.

The reservoir serves as a quiet retreat where visitors practice outdoor traditions like fishing, boating, and camping within designated areas. People who come here typically respect the natural setting by packing out their own waste and keeping noise levels low, habits that help preserve the peaceful character of the location.

The area closes from May to June each year to allow deer migration and becomes inaccessible in winter due to snow, making spring or fall the best times to visit. Check road conditions before arriving, plan ahead since cell service is limited, and inform someone of your plans for safety.

In September 2020, the Creek Fire swept through the area, forcing some campers to wade into the water for safety and requiring helicopter evacuations amid smoke and flames. This rare event showed how quickly wildfires can reshape the landscape and limit access to this remote mountain location.