The Johnston Ridge Observatory

Most visitors who want to get close to Mount St. Helens, drive the 48 miles on the Spirit Lake Highway to the Johnston Ridge Observatory.

Here you are a mere 5.5 miles from an active volcano. This is well within the former Red Zone which was restricted to visitors in the winter and spring of 1980. Only certain people where allowed into the Red Zone and one of those was David Johnston, a volcanologist, who was there to monitor the volcano.

Johnston was really not supposed to be there the morning of May 18 but out of kindness he switched shifts with a colleague who was busy meeting with some foreign graduate students.

At the time of the eruption, Johnston was 30 years old and he had been working as an volcanologist who specialized in the study of volcanic gases and how these gases might help in the prediction of volcanic eruptions. He was at Mount St. Helens as one of the many scientists that were here to help monitor the volcano and to carefully watch the bulge on the north side of the mountain that was growing by five feet a day.

On Saturday May 17, Johnston stationed himself outside a USGS RV at a location called Coldwater II, 5.5 miles from the volcano. On the following morning Johnston made some measurements and observations and then at 8:32 AM, he radioed the USGS headquarters in Vancouver, Washington: “Vancouver, Vancouver, this is it!”

This field sketch is from the approximate position of Coldwater II, the observation position of David Johnston on May 18, 1980.

This was the last radio transmission from Johnston.

At 8:32 AM there was a 5.1 magnitude earthquake under the volcano causing the north face to fall away from the mountain causing the largest landslide in recorded geologic history. The avalanche travelled 14 miles before coming to a rest. This uncovered the over-pressured core of the volcano, releasing ash, magma, and rocks, fifteen miles into the atmosphere. The eruption of Mount St. Helens was now underway.

Johnston’s body was never found. The ridge where he was on that fateful day in 1980 is now named after him.

The memorial to the 57 who lost their lives and it’s cause in the background. David A. Johnston is one of them. The memorial is a short hike from the Johnston Ridge Observatory and it is this viewpoint that is in the featured sketch.
The incredible vista of Mount St. Helens from the Johnston Ridge Observatory.