It is difficult to predict when an earthquake or volcano will erupt, however, some areas are more seismically active than others. That is because they are located along a fault line, or where tectonic plates collide, slide or move apart from one another. In the U.S., California Washington and Alaska, are seismically active areas. There are volcanoes in Alaska, Arizona, California, Colorado, Idaho, Mississippi, Missouri, Nevada, New Hampshire, New Mexico, Oregon, South Dakata, Texas, Utah, Virginia, Washington Wyoming. Alaska has many active volcanoes, some which have recently erupted. Washington's Mt. St. Helens, erupted in 2008. The other volcanoes have not been active for thousands or millions of years in the U.S. Since California is located along the active San Andreas Fault, it is very seismically active and experiences several earthquakes per day. Mount St. Helens is in the Cascade Range and is part of the Pacific Ring of Fire, which includes 160 active volcanoes. This volcano is in Washington State. That is a likely place for volcanic eruption to occur in the continental U.S. although it is difficult to predict where and when a volcano may erupt.