Although volcanic eruptions have occurred infrequently in California during the last few thousand years, the potential danger to life and property from volcanoes in the state is great enough to be of concern, according to a recent U.S Geological Survey (USGS) publication. the 17-page bulletin, "Potential Hazards from Future Volcanic Eruptions in California," gives a brief history of volcanic activity in California during the past 100,000 years, descriptions of the types of volcanoes in the state, the types of potentially hazardous volcanic events that could occur, and hazard-zonation maps and tables depicting six areas of the state where volcanic eruptions might occur. Although no quantitative probabilities are attached to any of the potential volcanic hazards, the USGS bulletin warns that "sooner or later a volcano in California will erupt again and the ever-expanding use of area near volcnoes increases the potential impact of an eruption on the state's economy and on the health and safety of its citizens.
