Rancho Castac or Rancho Castec was a 22,178-acre (89.75 km2) Mexican land grant in present-day Kern and Los Angeles counties, California, made by Governor Manuel Micheltorena to Jose Maria Covarrubias in 1843. The rancho in the Tehachapi Mountains lay between Castac Lake on the south and the present Grapevine on the north and included what is now the community of Lebec. The rancho is now a part of the Tejon Ranch. The word Castac is derived from Kashtiq, the Chumash-language name that the Chumash people gave to the area nearby.