Castaic () (Chumash: Kaštiq; Spanish: Castéc) is an unincorporated community and census-designated place (CDP) in northwestern Los Angeles County, California, United States. As of the 2020 census it had a population of 18,937.
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. Castaic is northwest of Los Angeles Union Station and northwest of the city of Santa Clarita.
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.
Name
The name Castaic is derived from the Chumash word Kaštiq, meaning "the eye". The Spanish and Mexicans later spelt the name in Spanish as Castéc. 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.
History
The Córdova family of California were the first settlers in the area. Modern Castaic began in 1887 when Southern Pacific set up a railroad siding on the line between Piru and Saugus Station, naming it "Castaic Junction". Between January and April 1890, the Castec School District adopted the new spelling, "Castaic".
Range War
Between 1890 and 1916, the Castaic Range War was fought in Castaic country over ranch boundaries and grazing rights. It was the biggest range war in U.S. history.
A feud started over Section 23, where the Stonegate subdivision is now. William Chormicle had legally bought the property, but William "Wirt" Jenkins was already storing grain on it and said he had filed for ownership. During a heated dispute, Chormicle and a friend shot and killed two of Jenkins's cowhands. They were acquitted in court.
Jenkins, however, was the local justice of the peace, with friends of his own, and the feud quickly grew into war. Former Los Angeles Rangers (among whom Jenkins had fought) and other notables were drawn in. The war claimed dozens of lives and foiled a negotiator, a forest ranger whom President Theodore Roosevelt had sent in to quell it.
Geography
Seismology
The area is seismically active. On January 3, 2015, a pair of earthquakes of magnitude 3.1 (location: , depth: ) and 4.2 (location: , depth: ), respectively, were reported about north of Castaic. The epicenter was from Santa Clarita, California.
Climate
This region experiences hot and dry summers, and cool, moderately rainy winters. During the months of June though September, the average high temperature ranges from the 90s F (30s C) to above . According to the Köppen Climate Classification system, Castaic has a hot-summer Mediterranean climate, abbreviated "Csa" on climate maps.
350 px|center|Topography of Castac Valley and Rancho San Francisco