Rancho Las Posas was a 26,623-acre (107.74 km2) Mexican land grant in present-day Ventura County, California.
His brother, Carlos Antonio Carrillo, was granted Rancho Sespe in 1833 by Governor Figueroa.
Captain José de la Guerra y Noriega (1779 –1858) was Comandante of the Presidio of Santa Barbara from 1827 to 1842.
José de la Guerra y Noriega, who had begun to acquire large amounts of land in California to raise cattle, purchased Rancho Las Posas from the Carrillo family in 1842.
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored.