|Mount St. Helens
May 19, 1980 eruption of Mount St. Helens.
Prior to May 18, 1980, 9,677 ft. Mount St. Helens was Washington's fifth-highest peak. Towering above Spirit Lake, this beautiful volcanic cone rose over 5,000 feet above its base.
Known to Native Americans as "Louwala-Clough", which means "smoking mountain". St. Helens was also nicknamed "Fuji-san of America" for it's resemblence to Japan's famous Mt. Fuji.
Formed within the last 40,000 years, Mount St. Helens is geologically young compared to the other major volcanoes of the Cascade Range and is considered the most active volcano in the range for the past 10,000 years or so.
Mount St. Helens was quite popular with mountaineers and had many routes on its snowy slopes and glaciers.
On March 20, 1980 a 4.2 earthquake was experienced on the mountain. On March 27, steam began to vent. By the end of April, the north side began to bulge. A second earthquake, of magnitude 5.1, triggered a collapse of the North Face causing the largest known debris avalanch in recorded history.
The magma burst into a large-scale pyroclastic flow, flattening forest and buildings over 230 square miles. More than 1.5 million metric tons of sulpher dioxide was released into the atmosphere. A plume of ash erupted for over nine hours, rising 12-16 miles above sea level and moving eastward at 60 mph, reaching Idaho by noon.
By 5:30 p.m. the ash column declined and less severe outbursts continued over the next several days.
The May 18, 1980 eruption released 24 megatons of thermal energy, and ejected over 0.67 cubic miles of material. The mountain was reduced in heigth by approx. 1,300 feet, leaving a one to two mile wide crater, 0.5 miles deep with it's north side open. 57 people died, nearly 7,000 big game animals and an estimated 12 million fish, from a hatchery also died in the eruption. 200 homes were destroyed or severly damaged. 185 miles of highway and 15 miles of roadways were also destroyed.
In progress, more to come.
The easiest way to reach Mt. St. Helens is from I-5. From exit 49 take 504 to the mountain.
Browse More Classics in Mount St. Helens
Mountain Project's determination of some of the classic, most popular, highest rated routes for Mount St. Helens:
Featured Route For Mount St. Helens
Easy Snow WA
: Mount St. Helens
This is the most common route up the mountain during the Winter and early Spring. Start at the Marble Mountain Sno-Park (2680') and follow the trail through the woods. Break out above treeline near 4600' and head up the fall line (generally aiming North), and connect with the Monitor Ridge route (might not be obvious) at about 7000', with Swift Glacier to your right. A little over 1000' of uphill from here gets you to the crater rim. Turn left (West) and traverse the rim for about 0.3 miles to m...[more] Browse More Classics in WA
3,000 ft (1 km) steam plume on May 19, 1982, two y...
Errett Allen on Mount St. Helens, 1974.
Photo by B...
Painting by Paul Kane Mount St. Helens erupting at...
Mount St. Helens and Spirit Lake prior to the May ...
Mount St. Helens the day before the 1980 eruption,...
April 10, 1980 eruption.
Harry Randall Truman (October 30, 1896 – May 18, 1...
Skirting a schrund on Mount St. Helens, 1974.
Volcanic ash in the Columbia River Gorge. Septembe...
panorama at the crater rim, october 2010