Editor’s note: This story was originally published in 2021. It has been edited to update dated references.
Wednesday marks the 42nd anniversary of the eruption of Mount St. Helens in Washington. It was an iconic, and at the time, terrifying event here in the Pacific Northwest.
The mountain exploded with the force of an atom bomb, killing more than 50 people, flattening forests, triggering mudslides, floods and dropped ash on 10 states.
While the High Desert was spared, there is a local connection. Two Central Oregonians were flying over the mountain when it erupted.
Chuck Rosenfeld, an Oregon State University geography and natural hazards professor who now lives in Sunriver, and John Seedee, a state police game officer from Bend, were approaching Mount St. Helens in a National Guard observation plane when the mountain erupted May 18, 1980.
“We were delayed by an administrative action that morning. Thank God we weren’t over the mountain at exactly at 8:30 because at 8:32 the mountain had the lateral blast,” said Rosenfeld. “It was a big steam blast eruption, but it was a hypersonic eruption that would have probably destroyed our aircraft.”
Rosenfeld took a series of now-famous photographs of the rising ash plume that reached nearly 80,000 feet and was filled with lightning.
“We were 17 miles to the south-southwest when the mountain erupted. There was a civilian aircraft carrying two geologists who had just passed the peak when it erupted,” he said. “They were very close to being swept up into the plume. They headed south to Portland. Our first sweep was to the west of the mountain where we took most of the photos that you see in the news media today.”
Rosenfeld and Seedee watched an avalanche off the north face of the mountain that filled the Toutle River Valley with debris nearly 600 feet deep.
They documented the river’s breach of the debris dam and subsequent flooding of the valley below.
“We followed the mudflow as fast as we could. We saw it knock out the bridge at Toutle. We were talking to National Guard operators who warned the Washington State Patrol to shut off I-5. A few minutes later, the mudflow actually made it underneath a railroad bridge and under the two I-5 bridges. Fortunately, police had stopped the traffic on I-5. Had those bridges gone with traffic moving, we would have had a lot more casualties than actually occurred.”
Despite losing a colleague in the eruption and observing all the devastation, Rosenfeld says he’s still fascinated by volcanoes.
“Here I am living in the shadow of Mount Mazama, Oregon’s high-risk volcano,” he said. “Mount Hood and the Crater Rocks area are also a relatively high risk, but everything is relative in geology terms to the shortness of a human life.”
