Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche. In a few moments this slab of rock and ice slammed into Spirit Lake, crossed a ridge 1,300 feet high, and roared 14 miles down the Toutle River. The avalanche rapidly released pressurized gases within the volcano. A tremendous lateral explosion ripped through the avalanche and developed into a turbulent, stone-filled wind that swept over ridges and toppled trees. Nearly 150 square miles of forest was blown over or left dead and standing. At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, gray ash fell over eastern Washington and beyond.
On May 17, 1980, Mount St. Helens was a symmetrical cone, a mountain so near perfection it was sometimes called "America's Mount Fujiyama." Photographers loved St. Helens because it looked the way a mountain is supposed to look: smooth sides, printed crest, fluted topping of snow. At its base, a clear, blue-green lake reflected an upside-down image of the mountain precisely enough to cause vertigo. It was a scene made for calenders and postcards. That was May 17, By the evening of May 18, Mount St. Helens was a smoking crater, hollowed-out and grey. It looked defiled, like the victim of some grisly crime. Mount St. Helens had burst into volcanic eruption at 8:32 that morning, exploding sideways with a blast so powerful it knowed down trees 17 miles away. When the ash cleared, the mountain had dripped in rank from Washington's fifth-highest peak, at 9,677 feet, to its thirtieth-highest, at 8,364 feet.
Mt. St. Helens had remained dormant for 123 years. In March of 1980 scientists recorded seismic tremors from the mountain. State officials ordered the residents of the area to evacuate and warned people not to hike in the area. However, not everyone took heed to the warnings. Thousands of acres of timber fell over like match sticks. Lakes clogged with mud. Spirit Lake, adjacent to the mountain, turned into a mud hole and was littered with timber. The eruption caused total devastation to the land, lakes, and forests. Miles away, the city of Yakima, Washington - population of 65,000- was affected the worst. Yakima was only inconvenienced by huge amounts of ash and clean up, while the people and the land near the mountain suffered total death and destruction. The fatality rate for Mt. St. Helens could of been much higher if not for the evacuation orders and the advances of technology.
Long before settlers arrived from the east, Mt. St. Helens was a sacred place to the local Indian tribes. They had been witnesses to its long history of eruptive behavior and ancient legends caused them to give the mountain a wide berth. Some of the names given to the mountain were Lawelatla ("One From Whom Smoke Comes"), Louwala-Clough ("Smoking Mountain"), Tah-one-lat-clah ("Fire Mountain") and the most commonly used name today Loo-wit ("Keeper of the Fire"). The local tribes would not fish in Spirit Lake, believing the fish, with heads like bears, held the souls of the evilest people who had ever lived. They also believed the lake shores were populated by a band of rogue demons. Only young warriors out to prove their bravery dared climb to the timberline and spend the night. Later, legends claimed the evil spirits of the mountain were punishing the local tribes for allowing the white men to settle at her feet.
The modern name, Mount St. Helens, was given to the volcanic peak in 1792 by Captain George Vancouver of the British Royal Navy, a seafarer and explorer. He named it in honor of a fellow countryman, Alleyne Fitzherbert, who held the title Baron St. Helens and who was at the time the British Ambassador to Spain.
Mount St. Helens, Washington, is the most active volcano in the Cascade Range. Its most recent series of eruptions began in 1980 when a large landslide and powerful explosive eruption created a large crater, and ended 6 years later after more than a dozen extrusions of lava built a dome in the crater. Larger, longer lasting eruptions have occurred in the volcano's past and are likely to occur in the future. Although the volcano seems to have returned to a period of quiet, scientists with the U.S. Geological Survey and University of Washington Geophysics Program continue to closely monitor Mount St. Helens for signs of renewed activity.
Stratovolcanoes, also known as composite cones, are the most picturesque and the most deadly of the volcano types. Their lower slopes are gentle, but they rise steeply near the summit to produce an overall morphology that is concave in an upward direction. The summit area typically contains a surprisingly small summit crater.
Mount St. Helens is a typical stratovolcano. The volcano is one of several that line-up to form the Cascade Range.
Mount St. Helens was built by many eruptions over thousands of years. In each eruption hot rock from inside the earth forced its way to the surface. The rock was so hot that it was molten, or melted, and it had gases trapped in it. In some eruptions the magma was fairly liquid. Its gases escaped gently. Lava flowed out of the volcano, cooled, and hardened. In other eruptions the magma was thick and sticky. Its gases burst out violently, carrying along sprays of molten rock. As it blasted into the sky, the rock cooled and hardened.
Mount St. Helens, located in southwestern Washington about 50 miles northeast of Portland, Oregon, is one of several lofty volcanic peaks that dominate the Cascade Range of the Pacific Northwest; the range extends from Mount Garibaldi in British Columbia, Canada, to Lassen Peak in northern California.