Castac Lake

Castac Lake
Castac Lake is visible from I-5.
Location	Lebec, Kern County, California
Coordinates	34°50′06″N 118°50′35″W / 34.8349730°N 118.8431683°W / 34.8349730; -118.8431683Coordinates: 34°50′06″N 118°50′35″W / 34.8349730°N 118.8431683°W / 34.8349730; -118.8431683
Type	saline, endorheic
Primary inflows	Cuddy Creek, Bear Canyon, Crane Canyon
Primary outflows	Grapevine Creek
Catchment area	56 sq mi (150 km2)
Max. length	1 mile (1.6 km)
Surface area	400 acres (160 ha)
Surface elevation	3,484 ft (1,062 m)

Castac Lake (also known as Tejon Lake) is a natural saline endorheic lake near Lebec, California. The lake is located in the Tehachapi Mountains just south of the Grapevine section of Interstate 5, and within Tejon Ranch. Normal water elevations are 3,482 feet (1,061 m) above sea level.

The lake lies in a natural sink at the eastern end of the Castac Valley, a rift valley formed along the Garlock Fault. The main inflows are Cuddy Creek and small intermittent streams originating in Bear and Crane Canyons, draining a total of 56 square miles (150 km²) into the lake. The lake itself was formed about 10,000 years ago, by the natural damming of water behind the alluvial fan of Cuddy Creek, blocking its natural northern outlet to Grapevine Creek. During most years the outlet sits about 12 feet (3.7 m) higher than the lake surface. During rare flooding events the lake does overflow into Grapevine Creek, which flows through a canyon into the San Joaquin Valley.

Although Castac Lake itself is saline, the abundance of freshwater springs nearby made it an attractive area for human settlement. The lake area was once the territory of the Castac and Emigdiano groups of Chumash people, who occupied the area between Tejon Pass and the modern Grapevine. Several Native American villages were located in the area, including the Emigdiano village of Sasau on the northern shore of the lake. The Chumash name for the lake was Kash-tük, or "my eyes". The lake was known as A-uva-pya, or "in his eyes", in Kitanemuk, and as Sasa-u, "at the eye", in Yokuts.

The lake was first seen by Spanish explorer Pedro Fages who in 1772 led the first European expedition to cross the Tehachapis via Tejon Pass into the San Joaquin Valley. Fages named the lake Salinas de Cortes and Tejon Pass the Portezuelo de Cortes. The lake's modern name may have originated from a later Spanish expedition circa 1806, in which Father José María de Zalvidea noted a Native American village called "Casteque" or "Kashtiq" near "[a lake of] pure salt water".