Eruption: The Untold Story of Mount St. Helens

by Steve Olson

always gave it female names: Loowit, which means “keeper of the fire”; Lawetlat’la, which means “the smoker”; or simply Si Yett, which means “the woman” in the Penutian language of the Yakima.

Suddenly, on March 30, 1956, the volcano violently exploded, devastating areas almost twenty miles away. But what was unusual about Bezymianny is that the volcano did not explode straight upward, as in the conventional image of an erupting volcano. It exploded sideways, ripping the side off the mountain and destroying everything in that direction while leaving the rest of the countryside unscathed.

“The blast from the explosion of a Soviet volcano in 1956 blew down trees 15 miles away,”

The volcanoes in Hawaii typically erupt a very different kind of lava than do the Cascade volcanoes. The basaltic lava in Hawaii, which is derived from a hot spot beneath the Pacific tectonic plate, has the consistency of raw honey when it erupts. Fed from summit vents or rifts that split the flanks of volcanoes, the lava flows downslope in pulsating streams. Explosive eruptions are infrequent, and the risk to human life from such eruptions is low.

The magmas that have created the Cascade volcanoes generally have a different consistency. As they make their way to the surface of the earth from the subducting oceanic plate, they often lose iron- and magnesium-rich crystals and gain silica from the melting of continental rocks. By the time the magma erupts, it has a consistency more like road tar than honey. This kind of magma can form stiff, sticky plugs in volcanic vents that bottle up the gases and pressure in a volcano. When the blockage gives way, explosive eruptions can result. The Hawaiian volcanologists had studied other kinds of volcanoes, but they were much more familiar with gradual eruptions of red-hot basalt than they were with explosive subduction-type volcanoes. However,

the distant volcano that Meriwether Lewis, when he was traveling up the Columbia River almost a century earlier, called “the most noble looking object of its kind in nature.”

Over the course of Roosevelt’s presidency, he and Pinchot did more to preserve America’s forests than anyone else in US history. By that measure at least, Roosevelt earned his spot on Mount Rushmore with Washington, Jefferson, and Lincoln.

When President Cleveland created the Mount Rainier Forest Reserve in 1897, Mount St. Helens was left out of the reserve, partly because of the commercial value of the forests right around the mountain. But an immense 1902 forest fire just south of the volcano dimmed private companies’ enthusiasm for the area. Five years later, Roosevelt and Pinchot succeeded in adding the area around the volcano to the renamed Columbia National Forest. That pushed the boundary of the national forest right up against Weyerhaeuser’s vast forestlands to the west.

On June 15, 1949, President Harry Truman signed the proclamation designating the Columbia National Forest the Gifford Pinchot National Forest.

Servicemen back from the war took their rapidly growing families into the woods on inexpensive family vacations. Outdoor companies like REI, founded in Seattle in 1938, began to sell lightweight and waterproof clothes and camping equipment, making it easier to camp, hike, and hunt. Hiking clubs like the Mountaineers in Washington State and the Mazamas in Oregon had been active since the end of the nineteenth century, but now the cognoscenti were joined by many more people who had a more casual but enduring connection to the outdoors. People came to the national forests to hike, bike, horseback ride, backpack, hunt, snowmobile, motorcycle, ski, swim, picnic, kayak, fish, camp, and simply drive.

By 1980, almost all of the old-growth forests more than two hundred years old were gone, with newer forests growing in their stead.

All around the mountain, Weyerhaeuser and other companies were logging right up to the tree line on soils so thin that trees would never grow back.

Mount St. Helens was the only volcano in the entire state—almost the only volcano in the entire northwest—that wasn’t within a national park, a wilderness area, or a recreation area.

never liked the looks of Mount St. Helens. It was doing things that volcanoes weren’t supposed to do, things that were difficult to understand. At this point, the geologists agreed that the bulge had to be the result of magma welling up inside the volcano and pushing on the mountain’s north flank.

The blast cloud reached him before he could put the key in the ignition. The car windows facing the volcano blew out. The Volvo quickly filled with burning hot ash. Blackburn tried to breathe, but the blast cloud contained little oxygen. His nose, mouth, and lungs filled with ash. Ash from Mount St. Helens tastes like chalk dust mixed with metal; it smells like a dry field stirred by the wind on a hot day.

As the ash cloud approached, sparks began to fly from ice axes, knives, and anything else made of metal. Ash clouds contain powerful electric charges caused by ash particles rubbing together, in the same way that rubbing balloons together generates static electricity. As a result, volcanic eruptions almost always contain intense displays of lightning.

“Somebody said it looked like a moonscape, but the moon looks like a golf course compared to what’s up there. . . . The ash is several hundred feet deep. There are tremendous clouds of steam coming up. There are enormous icebergs, big as a mobile home. A lot of them are melting, and as the icebergs melt . . . the ash caves in and creates enormous craters. There are a few fires about, on the edge of the ash flow, where logs are still exposed. . . . It’s an unbelievable sight.”

“Land management decisions are being made with the bulldozer and chainsaw.”

“It wasn’t just the volcano that gave us a feeling of dread—the whole gray, lifeless landscape made us apprehensive. .

The old-growth forests of the Green River were saved from logging, as were the forests surrounding the lava caves to the south of the volcano. The monument would be under the jurisdiction of the Forest Service, but it would be managed as a separate unit and have its own planners and supervisor. Fishing and hunting were allowed in parts of the monument, but road building was discouraged.

“The eruption was an act of God. But the deaths were an act of man, when man ignored weeks and weeks of God’s warnings.”

If the caldera under Yellowstone National Park were to erupt the way it did 640,000 years ago, ash could cover the entire United States, and the sudden cooling of the planet caused by volcanic aerosols would decimate harvests worldwide.

In a few minutes, the volcano blew down enough timber to construct an entire city. The toppled trees were covered by a thick layer of chalky gray ash, like a shroud thrown across the landscape.

Right on the edge of the blowdown zone, where the blast cloud finally ascended into the sky, temperatures were hot enough to kill the trees but the blast was not strong enough to blow them over. Today, the dead trees that were not salvaged are still there, a thin band of ghostly white snags facing toward the volcano.

Because much of the high country was still covered by snow when the volcano erupted, pocket gophers, deer mice, shrews, voles, and other small mammals were still in their burrows, and some of them survived the eruption.