This report evaluates the volcano-related hazards of the Lassen region, California, which is here defined as an area between the Pit River on the north and the southern limit of active Cascade volcanism, approximately 5-10 km south of the southern boundary of Lassen Volcanic National Park. Most active volcanism occurs in a zone about 40 km wide between Viola on the west and the eastern boundary of Caribou Wilderness Area, but sparser volcanism in the west extends the width of this zone to about 75 km. The report is based primarily on knowledge of hazardous phenomena observed at other, similar volcanoes and on recently published geologic mapping and geochronology (Clynne and Muffler, 2010; Christiansen and others, 2002; Clynne and others, 2008) applied to the volcano-hazards framework established by Miller (1989).