Eyewitness to History: The 1980 Eruption of Mount St. Helens

Author note: This article contains the memory of my great-grandfather Charles Mulvey who was working on the Hanford Site near Richland, Washington when Mount St. Helens erupted. A few days after the eruption, he wrote this short essay about his experience. It was recently found by my aunt Diane Izzo when she was looking through family effects. The text provided below has no alterations from the original.

May 20, 1980

Well, the Spirit Mountain did as the Indians have been telling us it would do. It spoke real loud and was heard as far as Spokane anyway. It seems Mount St. Helens still has a lot of life left.

So I guess I’ll make an attempt to give some of the sights, impressions, and feelings which I observed and felt during and after the eruption which occurred this past Sunday, May 18, 1980.

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Mount St. Helens has been gradually changing from its former inactive status to active with mostly relatively mild eruptions and steam, ash emissions. The officials concerned and those persons observing the volcano have repeatedly given warning of the serious potential of a major eruption.

Sunday morning at approximately 0830 a.m. Mount St. Helens erupted with an explosion which blew the top 1300 feet off of the mountain and formed a horseshoe shaped crater. A huge cloud of ash and debris was reportedly blown to an altitude of 60,000 feet.

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I was at work and doing my job assignment this day. I heard the blast and thought that that was no sonic boom but possibly a large dynamite explosion. The time is not definite but seemed to be just before 0900 a.m.

There was earth movement reportedly felt by others, however I felt no movement of which I was aware.

I continued with my work routines and sometime near 1000 I noticed the western sky getting dark and appeared smoky as if the fruit growers in the Yakima Valley were fogging to save the fruit crop. Of course, the day had started out clear, sunny and warm. Fruit fogging was out of the question.

The sky continued to darken rapidly and a radio transmission was heard telling all listeners that Mount St. Helens had erupted. More information would be transmitted as it was received.

By 1030 the sky was rapidly being covered with a huge, flat bottomed cloud which eventually covered all visible horizons completely blacking out the sun.

My job assignment was partly the responsibility of watching a pumping operation and the recording of operational data. At the 1100 time for a check of the pump and data the cloud had covered the sun and the northern and southern horizons and all except the east portions.

The westward facing field lamps were being activated. These field lamps light up with detection by a photo cell of approaching dark conditions.

By the time I had completed my periodic check of the pump operation and returned to the building, full darkness had occurred and the fallout of volcanic ash was underway. The darkness was equal to that of a moonless, starless, possibly cloudy stormy night.

During the next two hours the ash fall continued, with an appearance of a dry rain, if such were possible. The particles of ash ranged from a fine powder to a coarse sand. The coarse, sandy material was heavy, and the find powdery material is extremely light, almost a talcum powder.

At the 1300 time check of the pump, the ground and all horizontal exposed surfaces were covered with ash to a depth range from one-eighth to one-quarter inch deep. The ash was evenly distributed and created considerable dust when vehicles were driven.

Light conditions at 1300 required use of a flashlight to observe numbers and dials. The pump incidentally was stopped at 1315 hours due to the hazardous conditions.

The ash fall continued heavy until approximately 1430 when the sky lightened again to daylight. A light dust ash fall continued. A dusty haze filled the air and it was necessary to don dust filters or face masks for working outside. Some samples of ash were taken for souvenirs at this time.

The light ash fall continued for the remainder of the day and possibly throughout the night. A souvenir ash sample of this light ash fall was taken the following morning from a surface which was clean at the time the initial ash fall samples were taken.

The volcanic ash fall covered a large area of eastern Washington. Roads and highways were closed due to extremely dusty conditions which made driving very difficult. People were warned to stay off the roads and to stay indoors.

The severity of the ash fall was relevant to the depth of the ground cover. This ranged from a trace to several inches. Towns and cities within the fallout area have encountered difficulty with removal of the volcanic ash.

The bus which picked us up at work and transported us home was a casualty of the dusty conditions. Dust clogged the filters and was pulled into the motor which failed due to the abrasive ash. Only the front part of the bus was visible as it approached. It was lost in dust back from the front wheels.

A light ash fall continued the following day with extremely dusty air conditions. Only essential work was being done, and usually only necessary stores (grocery, etc.) were open.

High winds have swept the area since the eruption which continually creates more dust conditions.

The featured image is of the eruption column from Mount St. Helens on May 18, 1980. (USFS)