There are 73 potentially_active volcanoes located in western USA. Volcanoes are awesome manifestations of the fiery power contained deep within the Earth. These formations are essentially vents on the Earth's surface where molten rock, debris, and gases from the planet's interior are emitted.

The United States ranks third, behind Indonesia and Japan, in the number of historically active volcanoes. About 10 percent of the more than 1,500 volcanoes that have erupted in the past 10,000 years are located in the United States.

When thick magma and large amounts of gas build up under the surface, eruptions can be explosive, expelling lava, rocks and ash into the air. Less gas and more viscous magma usually mean a less dramatic eruption, often causing streams of lava to ooze from the vent.

Few natural forces are as spectacular and threatening, or have played such a dominant role in shaping the face of the Earth, as erupting volcanoes. Volcanism has built some of the world's greatest mountain ranges, covered vast regions with lava and triggered explosive eruptions whose size and power are nearly impossible for us to imagine today.

Between 1980 and 1990, volcanic activity killed at least 26,000 people and forced nearly 450,000 to flee from their homes. A large eruption can be extremely dangerous for people living near a volcano. A thick ash deposit quickly spreads over the area..

On Saturday, Nov 03, 2007, Mt St. Helens volcano in the State of Washington was still showing continuing lava dome growth. I wonder when it will erupte again? Will you be living downwind?