The north face of the mountain collapsed during the eruption of Mount St Helens on May 18, 1980, causing a huge landslide on the morning of the eruption. The magma burst outward causing a hurricane-force blast of hot gas, ash and rock. Following are some fast facts about the eruption:
- 3 = minutes of the initial blast (some slopes were blasted all the way down to bedrock).
- 15 = days it took the ash cloud produced by the eruption to circle the globe.
- 57 = people who died; most from asphyxiation after inhaling hot ash.
- 230 = square miles damaged by the eruption.
- 7,000 = estimated number of large game animals (deer, elk, bear) killed.
- 8,300 = feet; height of Mount St. Helens post-eruption (from 9,600' prior to it).
- 22,000 = square miles covered in ash.
- 110,000 = number of acres set aside as a National Volcanic Monument.
- 520,000,000 = tons of ash
- 1,000,000,000+ = estimated cost of damages in dollars.
Photo of nearby Yakima, WA, at 1:00 pm on the day of the eruption.
In summary, the eruption of Mount St. Helens is the deadliest and most economically destructive volcanic event in the history of the US.
We visited the area along Highway 99 with our first stop at the Monument boundary.
This viewpoint provided our first view of the blast area that killed trees up to 17 miles away). Initially, scientists expected the recovery of the area to take hundreds of years. That has proven to be very inaccurate as new vegetation has taken hold in the destroyed forests much sooner. Mount St. Helens is in the foreground, but shrouded by clouds in both photos.
We continued south on Highway 99 to Cascade Peaks Viewpoint. There is a small Visitor Center here and interpretive signs along the viewpoint.
The mountain is still shrouded in clouds, but the base is a bit more visible (we are hoping the clouds lift!) from this location.
Spirit Lake is visible from several viewpoints including Donnybrook. A massive landslide during the eruption created huge waves on the lake that pulled trees, topsoil and vegetation into the water. This completely altered the chemistry with more bacteria growing in the lake than had ever been recorded in natural water. Gases were produced that made the lake bubble and all visible life was killed. Amazingly, in three years the lake began to recover. Ten years after the eruption the water had almost fully returned to its previous pristine level. Today, there is more aquatic life in Spirit Lake than before the eruption. The power of Mother Nature is pretty darn incredible!
The Smith Creek Overlook is normally the best location along Highway 99 to see the mountain. The cloudy weather continued to shroud the top of the mountain, although you can see the recovering forests around the base and in the nearby valley. Whenever our curious doggy, Sadie, sees a wall, she likes to jump up on it to see what's on the other side.
Windy Ridge is the end of the road on Highway 99 (and as close as you can get to Mount St. Helens from the east).
The "pumice plain" seen in the photo below is where a massive landslide and multiple waves of hot gases, pumice, and ash covered the area. Today, tenacious plants are starting to grow again on the plain. Big game wildlife have also returned to the area.
It was really interesting to learn more about the Mount St. Helens eruption as we both vividly remember the news images that were broadcast at the time. But, that will not be the last eruption from this mountain. It is listed as one of the top 10 "most volatile" volcanoes in the world and will likely erupt again...but no one can say when!
There is no admission fee to this national monument. For additional information about the national monument, check out their website at www.fs.usda.gov