Mount St. Helens, Stratovolcano in Skamania County, Washington, US

Mount St. Helens is a stratovolcano in Washington State with a horseshoe-shaped crater at 2549 meters (8363 feet) elevation. The flanks show exposed rock walls and ash fields, while the summit area features a slowly growing lava dome.

The eruption on May 18, 1980 tore away the entire north face of the mountain and transformed the landscape into a moonscape of mud and debris. Earlier eruptions occurred in the 19th century, but none matched the scale of this modern disaster.

The mountain is Lawetlat'la to the Cowlitz and Loowit or Louwala-Clough ("fire mountain" or "smoking mountain") to the Klickitat, who linked it to a beautiful female spirit fought over by Wy'east (Mount Hood) and Pahto (Mount Adams). The name St. Helens honors Alleyne FitzHerbert, 1st Baron St Helens, a friend of explorer George Vancouver.

The Johnston Ridge Observatory offers direct views of the crater and the surrounding blast zone throughout the year. Hiking trails lead through the recovery zones, though some routes remain closed in winter due to snow.

The crater holds Crater Glacier, which formed after the 1980 eruption and by 2004 covered about 0.36 square miles, split by the lava dome into two lobes. Its ice is all post-1980, yet its volume roughly equals that of all eleven glaciers that existed before the eruption.