Translated the word "penasquitos" means "little cliffs" in reference to the rugged palisades that rim the long valley. Originally built as a modest adobe in 1824 and then incorporated into a rancho in 1862 by U.S. Army Capt. George Alonzo Johnson, the ranch house was acquired in 1974 by San Diego County as a focal point to develop Los Penasquitos Canyon Preserve. Its history includes ownership in 1921 by two of San Diego's best known cattlemen, George Sawday of Witch Creek near Ramona and Oliver Sexon, a county under-sheriff.