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 lies 52 miles Northeast of Portland, Oregon and 98 miles (158 km) south of Seattle. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a friend of explorer George Vancouver who surveyed the area in the late 18th century. The volcano is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire.
Mount St. Helens is best known for its major eruption on May 18, 1980: the deadliest and most economically destructive volcanic event in U.S. history. Fifty-seven people were killed. 200 homes, 47 bridges, 15 miles of railways, and 185 miles of highway were destroyed. A massive debris avalanche, triggered by a magnitude 5.1 earthquake, 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 0.6 cubic miles in volume. The 1980 eruption disrupted terrestrial ecosystems near the volcano. By contrast, aquatic ecosystems in the area greatly benefited from the amounts of ash, allowing life to multiply rapidly. By six years after the eruption, most lakes in the area returned to their normal state.
After its 1980 eruption, the volcano had continuous volcanic activity until 2008. Geologists predict that future eruptions will be more destructive, since the configuration of the lava domes there require more pressure to erupt. Despite this, Mount St Helens is a popular hiking spot, and it is climbed year-round. In 1982, the Mount St. Helens National Volcanic Monument was established by U.S President Ronald Reagan and the U.S Congress.
Native American lore contains numerous stories to explain the eruptions of Mount St. Helens and other Cascade volcanoes. The most famous of these is the Bridge of the Gods story told by the Klickitat people. The mountain is also of sacred importance to the Cowlitz and Yakama tribes that also live in the area. They find the area above its tree line to be of exceptional spiritual significance, and the mountain (which they call "Lawetlat'la", roughly translated as "the smoker") features prominently in their creation story, and in some of their songs and rituals. In recognition of its cultural significance, over 12,000 acres of the mountain (roughly bounded by the Loowit Trail) have been listed on the National Register of Historic Places. Other area tribal names for the mountain include "nšh´ák´" ("water coming out") from the Upper Chehalis, and "aka akn" ("snow mountain"), a Kiksht term.