Not much information is given in the National Historic Landmarks Program website about the Los Alamos Ranch House.

It was designated a landmark on April 15, 1970. The statement of significance is listed as: "Probably the finest surviving example of the Mexican period traditional one story adobe ranchhouse in its rural setting, Rancho Los Alamos was established about 1840 by the son of the Commandant of the Santa Barbara Presidio. Los Alamos was a favorite overnight stopping place for wayfarers passing over El Camino Real between Santa Barbara and Monterey."

It is currently private property a short way West of the town of Los Alamos, California on State Highway 135. The house cannot be seen from the road, however.