Eruptions and associated hazards are a threat to human settlements largely in proportion to the encroachment of these settlements upon volcanoes. Special characteristics that set them apart from other natural hazards heighten the danger posed by volcanoes. In general, two strategies dominate plans to preserve public safety: development of an elaborate warning and evacuation system and enforcement of a policy of restricted access to danger areas around the volcano. Information about the volcano's beauty, resources associated with it, and its periodic eruptions has appeared in Indian folklore, depictions by explorers, missionaries, and settlers, and in the more systematic writings of naturalists and scientists. To examine the issue of communicating threat information to citizens at risk from an active volcano the current eruptive sequence at Mt. St. Helens has been examined. A communication channel is a mechanism through which a message is transmitted. Emergency management authorities, police, firefighters, friends, and neighbors are all clearly sources.