Rancho Los Alamos

Rancho Los Álamos was a 48,803-acre (197.50 km2) Mexican land grant in present-day Santa Barbara County, California given in 1839 by Governor Juan Alvarado to José Antonio de la Guerra, a son of José de la Guerra y Noriega.

[2] Concepción Ortega, who married José de la Guerra, came to live at the adobe ranch house.

[3] 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.

[6] In 1876, San Francisco financier Thomas Bell along with his son John S. Bell, and James B. Shaw, purchased acreage from Rancho Los Álamos and the neighboring Rancho La Laguna.

Both families allocated a half square mile from each of their new ranches to create the Los Alamos town site with "Centennial Street" as the central thoroughfare.