Castaic (/kəˈsteɪ.ɪk/ ⓘ) (Chumash: Kaštiq;[3] Spanish: Castéc)[4] is an unincorporated community and census designated place (CDP) in the northwestern part of Los Angeles County, California, United States.

[5] Tens of thousands of motorists pass through Castaic daily as they drive to or from Los Angeles on Interstate 5 (the Golden State Freeway).

Castaic Lake is part of the California Water Project and is the site of a hydro-electric power plant.

The Castaic Range War went on for decades in the late 19th and early 20th centuries resulting in dozens of deaths before hostilities ceased in 1916.

Castec is first mentioned on old boundary maps of Rancho San Francisco, as a canyon at the trailhead leading to the old Chumash camp at Castac Lake (Tejon Ranch), which is intermittently wet and briny.

The war claimed dozens of lives and foiled a negotiator, a forest ranger whom President Theodore Roosevelt had sent in to quell it.

[12][13][14][15] Castaic has the last traditional cattle roundup—with horses, lariats, and branding irons—in Los Angeles County.

Members of the Cordova family were scouts for the U.S. Army during the Mexican War in 1846 and helped identify bodies during the St. Francis Dam disaster in San Francisquito Canyon in 1928.

Operations scaled back in 1967 when the government seized around 1,000 acres (400 ha), including the ancestral ranch-house, for the planned Castaic Lake and dam.

According to the 2010 United States Census, Castaic had a median household income of $106,538, with 7.0% of the population living below the federal poverty line.

[citation needed] There were 5,932 housing units at an average density of 815.0 per square mile (314.7/km2), of which 4,843 (84.2%) were owner-occupied, and 908 (15.8%) were occupied by renters.