page_title: Mount St. Helens
hierarchical_section_title: Mount St. Helens
caption_attribution_description: Plumes of steam, gas, and ash often occurred at Mount St. Helens in the early 1980s. On clear days they could be seen from Portland, Oregon, 50&#160;mi (80&#160;km) to the south. The plume photographed here rose nearly 3,000&#160;ft (910&#160;m) above the volcano's rim. The view is from Harrys Ridge, 5&#160;mi (8&#160;km) north of the mountain.
context_page_description: Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 50 miles northeast of Portland, Oregon and 96 miles south of Seattle, Washington. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a friend of explorer George Vancouver who made a survey of the area in the late 18th century. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. This volcano is well known for its ash explosions and pyroclastic flows.
  Mount St. Helens is most notorious for its major eruption on May 18, 1980, the deadliest and most economically destructive volcanic event in US history. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles of railways, and 185 miles of highway were destroyed. A massive debris avalanche, triggered by an earthquake of magnitude 5.1, caused a lateral eruption that reduced the elevation of the mountain's summit from 9,677 ft to 8,363 ft, leaving a 1 mile wide horseshoe-shaped crater. The debris avalanche was up to 0.7 cubic miles in volume.
context_section_description: Mount St. Helens (known as  Lawetlat'la to the Indigenous Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 50 miles (80 km) northeast of Portland, Oregon and 96 miles (154 km) south of Seattle, Washington. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a friend of explorer George Vancouver who made a survey of the area in the late 18th century. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. This volcano is well known for its ash explosions and pyroclastic flows.
  Mount St. Helens is most notorious for its major eruption on May 18, 1980, the deadliest and most economically destructive volcanic event in US history. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles (24 km) of railways, and 185 miles (298 km) of highway were destroyed. A massive debris avalanche, triggered by an earthquake of magnitude 5.1, caused a lateral eruption that reduced the elevation of the mountain's summit from 9,677 ft (2,950 m) to 8,363 ft (2,549 m), leaving a 1 mile (1.6 km) wide horseshoe-shaped crater. The debris avalanche was up to 0.7 cubic miles (2.9 km³) in volume. The Mount St. Helens National Volcanic Monument was created to preserve the volcano and allow for the eruption's aftermath to be scientifically studied.
  As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted. The largest of the dacite domes formed the previous summit, and off its northern flank sat the smaller Goat Rocks dome. Both were destroyed in the 1980 eruption.
caption: 3,000 ft (1 km) high steam plume on May 19, 1982, two years after its major eruption
exif: {}