About Mount St. Helens

Mount St. Helens is part of the ring of fire encircling the Pacific Ocean. It was created and is continually being changed by the collision of the North American and the Juan de Fuca Tectonic Plates. Mount St. Helens is the youngest and most active Cascade Range volcano, born 40,000 years ago. It erupts roughly once each century.

After lying dormant for 123 years, Mount St. Helens again spewed steam and ash on March 27, 1980 – a prelude that put geologists on alert for a major volcanic event. But what occurred on May 18, 1980, went beyond what anyone had envisioned. A 5.1 magnitude earthquake from within Mount St. Helens triggered the collapse of the mountain’s north flank, releasing the largest landslide in recorded history and a volcanic eruption equal in power to 500 atom bombs. As much as a cubic mile of volcanic material shot upward and sideways. The lateral blast traveled at more than 300 miles per hour with temperatures in excess of 600 degrees Fahrenheit, destroying 230 square miles of forest. Within seconds, the trunks of thousands of 150-foot-tall, old-growth Douglas firs snapped like toothpicks. Rock, snow and ice roared down the mountain at speeds of more than 100 miles per hour. Ash rained down over 22,000 square miles, blew more than 12 miles into the atmosphere and circled the globe in 17 days. When the ash finally cleared, the mountain was reduced by 1,313 feet.

Although the Forest Service and local authorities had worked diligently to keep visitors away, 57 people were killed. Most large mammals on Mount St. Helens – mountain goats, black bears and thousands of elk and deer as well as most fish, amphibians, insects and birds – perished.

The entire world witnessed the power and lessons of the Mount St. Helens eruption. In response, the President and Congress created the 110,000-acre National Volcanic Monument with the following mission:

  • Protect the geologic, ecological and cultural resources, allowing for natural recovery and ecological succession.
  • Protect the significant features of the Monument.
  • Provide for recreational use, including interpretive facilities.
  • Ensure public health and safety.
  • Permit scientific study and research within the Monument.

The Recovery

As violent and unforgiving as it was, the May 18, 1980 eruption is just one event in the history of Mount St. Helens. Given the relatively short perspective of 32 years – not to mention the renewed volcanic activity – it is astounding to see how Mount St. Helens continues to transform. The past quarter-century has been characterized by rebirth and renewal. Within the crater a new lava dome began rising in 1986, rebuilding the mountain. A new glacier has established itself on the crater floor. And since early October 2004, a second lava dome has grown at a rate as high as a dump-truck load in volume every second. At this pace, scientists estimate Mount St. Helens could return to its pre-1980 eruption height of 9,677 feet in less than 200 years – just a blink of the eye in geologic time.

Remarkably, plant and animal life has reestablished itself far faster than expected. Beetles were among the earliest animals to return and over 300 kinds now flourish. Lupines, members of the pea family, were among the first plants to grow in the deep deposits of volcanic ash. Scientists learned that lupines drive ecological recovery by creating islands of rich nutrients that promote the establishment of other plant species. Millions of new trees, elk, deer, cougars, bobcats, bears, birds and fish have also returned to the areas so profoundly altered in 1980.

Mount St. Helens is a living laboratory. It has become one of the most remarkable areas of geological and ecological disturbance and restoration in the world. The lessons learned from this volcano have been shared with hundreds of millions of people around the world through scientific papers and popular articles, books and broadcast media. These lessons have also aided in the management of lands impacted by wildfire, mining and logging.

Mount St. Helens awoke again in 2004 and has entered a state of continuous eruption. News crews have come from all over the world; visitors have flocked to the mountain and the Volcano Cam Web site. From September 2004 to March 2005 the Web site received more than 342 million hits, averaging 1.8 million per day. Located near the regional population centers of Seattle and Portland, Mount St. Helens has also returned to its role as a leading recreation area and visitor attraction with more than 500,000 visitors a year.