Thompson & West, 1883, History of San Luis Obispo County California, Oakland Patrick Washington Murphy Patrick Washington Murphy (September 11, 1840 in Missouri – November 1, 1901 in San Francisco) operated Rancho Santa Margarita, and the adjacent Rancho Atascadero, and Rancho Asuncion, altogether comprising about 61000 acres from his Rancho Santa Margarita headquarters.