Mount St Helens Facts

Here are some facts about Mount St Helens, the famous volcano.

  • Mount St Helens is located in Washington State, in the northwestern part of the United States. It is almost 100 miles from Seattle, and 50 miles from Portland.

  • The volcano is 4,400 feet high at its highest point, and the base is about 6 miles across. Snow on the upper slopes of the volcano is often 15 feet deep.
  • The deadliest volcanic eruption in the US occurred at Mt St Helens on May 18, 1980. 57 people were killed, 250 homes destroyed, and almost 200 miles of highway destroyed.
  • Some of the first creatures to return to the volcano after the 1980 eruption were beetles and spiders. Scientists helped wild salmon to return by transporting them to streams in large tanks.
  • An eruption several times more powerful than the 1980 eruption took place about 3,600 years ago. It caused Native American Indians in the area to abandon their hunting grounds.
  • Most of Mount St Helens is less than 3,000 years old. This makes the volcano younger than the Great Pyramid in Egypt and Stonehenge in England.

Mount St Helens

  • The volcano erupted without stopping from September, 2004 to January, 2008. During this time, the Crater Glacier was split into two and the volcano settled about a half inch.
  • In August, 1982, Mount St Helens was declared to be a National Volcanic Monument. The site covers 110,000 acres and an estimated 1.5 million people visited between 1982 and 1989.
  • Like all volcanoes, Mount St Helens is constantly growing and changing shape because of the accumulation of erupted material. Since late 2004, a second lava dome has increased in volume by several square metres every second.
  • Although hiking up the mountain is popular, another popular way to see what is happening on the volcano is with the official VolcanoCam. The website attracts an estimated 1.8 million viewers every day. Click here to check it out.

What next? Discover more volcano facts or visit the Primary Facts Mountain resources page.