There are over 100 volcanoes in Alaska, 54 of which are considered historically active. A historically active volcano is one that fits one of the following criteria: (1) a documented or strongly suspected eruption since the year 1700, (2) persistent fumaroles near boiling point, (3) significant deformation with a volcanic cause, or (4) an earthquake swarm with a volcanic cause (Cameron and Schaefer 2016). Alaska’s national parks, preserves, and monuments contain a total of 14 historically active volcanoes (Figure 1). In addition, there are numerous other volcanoes within Alaska’s parks that are not considered historically active, but which could erupt at some point in the future. Volcanic Hazards in Alaska’s National Parks (U.S. National Park Service)