Mount St. Helens National Volcanic Monument

On the morning of May 18, 1980, a magnitude 5.1 earthquake triggered the collapse of the summit and north flank of Mount St. Helens and formed the largest landslide in recorded history.

Gas rich magma and super-heated groundwater trapped inside the volcano were suddenly released in a powerful lateral blast. In less than three minutes, 230 square miles of forest lay flattened. The hot gas and magma melted the snow and ice that covered the volcano. The resulting floodwater mixed with the rock and debris to create concrete-like mudflows that scoured river valleys surrounding the mountain.

A plume of volcanic ash and pumice billowed out of the volcano reaching a height of 15 miles and transformed day into night across Eastern Washington. Avalanches of super-heated gas and pumice, called pyroclastic flows, swept down the flanks of the volcano. While the landslide and lateral blast were over within minutes, the eruption column, mudflows and pyroclastic flows continued throughout the day and following night.

By the following morning major eruptive activity had ceased and the landscape appeared to be a gray wasteland. More than two years after Mount St. Helens erupted, Congress created the 110,000-acre National Volcanic Monument for research, recreation, and education. Ronald Reagan signed public law 97-243 on Aug. 26, 1982, formally designating the Mount St. Helens National Volcanic Monument. From this wasteland, new life soon emerged and thrived. The following decades have offered insight into the biological recovery of ravaged landscapes.

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Multimedia

Each year, over 10,000 students travel to Mount St. Helens to see the dramatic effects of the 1980 volcanic eruption, and observe how plants and animals have responded.

• Mount St. Helens Photos

  

  View historic Mount St. Helens photos on Flickr.

  View photos

• Poster of a Mountain Reborn

  

  View a high-resolution poster depicting Mount St. Helens, A Mountain Reborn, created by the Washington Department of Natural Resources.

  View poster

• Video Library

  

  View a range of videos about the story of Mount St. Helens violent eruption to the legacy of transformation and biological research on the mountain.

  View videos

Science & Research 

U.S. Forest Service:

• Mount St. Helens: A Living Laboratory for Ecological Research (Forest Service)
• Past, present, and future research on Mount St. Helens (Forest Service)
• Mount St. Helens - Frequently Asked Questions (Forest Service)
• Mount St. Helens’ many ecological lessons captured in new book (Forest Service)
• Promoting STEM education at Mount St. Helens- Interactive Story Map of a Field Trip with Inner City Youth Institute by Mathilda Bertills
• The Spirit Lake dilemma: Engineering a solution for a lake with a problematic outlet (Forest Service)

U.S. Geological Survey:

• 1980 Eruption Geological Events (USGS)
• 2004-2008 Dome Building Eruption (USGS)
• Publication: A Volcano Rekindled: The Renewed Eruption of Mount St. Helens, 2004-2006 (USGS)
• Publication: Eruptions of Mount St. Helens: Past, Present, and Future (USGS)
• Ash Cloud Simulations - This simulation shows where ash would go if Mount St. Helens erupted today (USGS)
• Visit Living with a Volcano in Your Backyard for hands on student activities. (USGS)
• Cascades Volcano Observatory (USGS)
• Map: Interactive Map of Monitoring Equipment and Seismic Activities on Mount St Helens  (USGS)

Visitor & Stewardship Information

• Mount St Helens Recreation information 
• Johnston Ridge Observatory
• Mount St. Helens Climbing information
• Attention Teachers: Mount St. Helens Field Trip planning
• Visit Mount St Helens Institute for information about volunteer opportunities, events & more.
• Mount St. Helens Science and Learning Center: www.mshslc.org