One of the most well known landmarks of the Pacific Northwest is an active volcano known as Mt St Helens. Known for the enormous explosion at Mt St Helens volcano in 1980, a visit to this area is still an impressive sight. The mountain is located east of Interstate 5 in southern Washington, very close to Vancouver and Portland; it's also an easy drive from Seattle, which is 96 miles to the north.

Mt St Helens volcano has experienced a surge of activity following steam and ash eruptions in 2004, and tourism has increased since the recent eruptions as well. Geologists were unsure what the volcano would do, so access was limited for quite some time, even to the observatory that was 5 miles away from Mount St Helens.

Scientists were observing the volcano during this period of increased activity, such as frequent, low magnitude earthquakes and the obvious swelling of the lava dome. This area of the crater, which was blown away in the 1980 explosion, was the epicenter of the eruption, and was the first to show signs of renewed activity at Mt St Helens volcano.

Washington State Map

The Mt St Helen lava dome is a result of a series of events, so this mountain has what is known as a composite dome. The building of the lava dome at Mount St Helens is an interesting activity to witness as an observer and as a scientist. Dome building is like a tube of toothpaste that occasionally gets squeezed. The composite dome of Mt St Helen is formed from small eruptions, the breaking apart of material from previous eruptions, and the occasional burst of magma that breaks parts of the dome open.

The eruption that occurred in 1980 caused the dome of the Mt St Helen volcano to explode and shoot plumes of hot ash thousands of feet into the air. The northern side of the mountain was blown off in the force of the Mt St Helens eruption that measured a 5.1 on the Richter.

Two years after the Mt St Helens Eruption, 110,000 acres were set aside as a National Volcanic Monuments, one of the most visited Washington State Parks.

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. The eruption lasted 9 hours, but Mount St Helens and the surrounding landscape were dramatically changed within moments. Now, this area and Mt St Helens is carefully monitored for activity, and the areas that were devastated by the Mt St Helens eruption are left to recover naturally.

The activity at Mt St Helens has died down since last year, so you can see the action and a north view from the Johnston Ridge observatory. There are exhibits, access to a hiking trail, an information desk, plenty of parking, and a spacious viewing plaza. Be sure to enjoy the views from this observatory when you visit Mt St Helens volcano on your next Washington vacation.