Lake Mathews

Lake Mathews is a reservoir in Riverside County nestled in the foothills of the Temescal Mountains. The body of water stretches roughly 4 miles (6.4 km) long and 2 miles (3.2 km) wide, holding around 182,000 acre-feet behind a dam in Cajalco Canyon.

Construction of the dam began in 1933 and was completed in 1939. Water deliveries through the Colorado River Aqueduct started in 1941, supplying cities across the region through the Metropolitan Water District of Southern California.

The name honors W.B. Mathews, an attorney who helped shape water law and supported the formation of the regional water district. The surrounding area remains mostly closed to the public, allowing the land to function as a protected zone for rare wildlife.

The site is not open to the public, as it serves as the endpoint of a long-distance water supply system and as a wildlife preserve. Visitors can only view the reservoir from outside, such as from public roads in the surrounding area.

The adjacent Lake Mathews Estelle Mountain Reserve covers around 13,000 acres and protects the Stephens's kangaroo rat, a rare rodent. In winter, the area serves as a retreat for eagles that hunt along the water.

Location: California

Elevation above the sea: 424 m

GPS coordinates: 33.84191,-117.44076

Latest update: December 5, 2025 22:28