An earthquake of moment magnitude Mw=6.5 struck the central coast of California in a region of sparse development and low population density. Because of its location halfway between San Francisco and Los Angeles, both areas of intense research into earthquakes and their societal effects, the San Simeon earthquake was documented by a large group of scientists and engineers. There was a surprising amount of liquefaction and related ground damage at relatively low levels of ground shaking away from the epicenter. While the structural damage was less than expected given the magnitude of the earthquake, the event has relevance as a characteristic scenario anticipated for moderate risk regions in other parts of the country that have moderate seismic risk and infrequent earthquakes and a largely unretrofitted building stock. The report offers lessons learned that would help improve the mitigation of future losses of life and property. The downtown area of Paso Robles suffered the most severe structural damage. In addition to the collapse of a two-story unreinforced masonry (URM) building, which caused two fatalities when people tried to flee the collapsing building, there were numerous buildings throughout the area, including many URM buildings, that suffered significant damage and had to be demolished. Life safety issues arose with the failure of a number of industrial storage systems. In addition to structural and nonstructural performance, the report covers seismological, geological, and geotechnical effects; performance of lifelines; emergency response, recovery, and public policy implications. This 78-page report was prepared by the EERI reconnaissance team, except for chapter 4 on