Rancho San Miguel was a 4,694-acre (19.00 km2) Mexican land grant in present-day Ventura County, California given in 1841 by Governor Juan Bautista Alvarado to Felipe Lorenzana and Raymundo Olivas.
[1] The grant encompassed the area of present-day City of Ventura not within Rancho Ex-Mission San Buenaventura, with the Santa Clara River marking its southern boundary.
Raymundo Olivas (1801-1879), born in Los Angeles, joined the Mexican Army at the age of 16 and was assigned to the Presidio of Santa Barbara.
In return for their army service, Olivas and Lorenzana, were granted one and a half square leagues in 1841.
[2] 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.