Courtright Reservoir, body of water

Courtright Reservoir is a large body of water in the Sierra Nevada surrounded by granite formations and coniferous forest at over 8000 feet elevation. Built in the late 1950s with a dam standing over 300 feet tall, it stores water used for hydroelectric power generation through an innovative pumped storage system that moves water between two reservoirs based on electricity demand.

Courtright Dam, a 315-foot rock-fill structure in Helms Creek canyon, was completed in 1958 and is owned by Pacific Gas and Electric. In 1984 the Helms Pumped Storage Powerhouse was added, linking the reservoir with Wishon Reservoir downstream. Water released through the 1,212 MW Helms plant generates power at peak demand, then is pumped back up when demand is low.

Courtright's granite domes draw rock climbers from around the world, and its 8,170-foot elevation and dark skies attract local astronomers such as members of the Central Valley Astronomers. Campers, anglers, boaters and 4x4 drivers use the reservoir in warmer months. Visitors should know that ticks in the area have transmitted tick-borne relapsing fever, and yellow-bellied marmots can carry cryptosporidium.

The winding mountain roads to the reservoir require careful driving, especially during busy weekends or bad weather, so arriving early ensures parking availability. Be prepared for rapidly changing conditions at this high elevation by bringing proper gear and checking current road and weather information before your trip.

The Helms Power Plant sits in a chamber carved from solid granite 1,000 feet underground at the north end of Wishon Lake. Its reversible turbines generate 1,212 MW when water drops from Courtright to Wishon, then pump the water back uphill when demand falls. The plant was added in 1984, turning Courtright into the upper reservoir of a pumped-storage system.