North Dakotans are familiar with severe weather. The state is no stranger to tornadoes, hailstorms, blizzards, and floods. But geologically, North Dakota is quite stable. Since 2010, the state has recorded thirty-one earthquakes. That might sound like a lot, but by comparison, California can experience more than thirty-five earthquakes in just twenty-four hours.
One geologic feature North Dakotans do not worry about is volcanoes. There are no volcanoes in the state. In September 1804, however, Lewis and Clark were interested in volcanoes. Lewis wrote of walking all day expecting to see a volcano reported to be in the area, but they never found it. Lewis and Clark did not actually see volcanoes until they reached the Pacific Coast. On November 25, 1805, Lewis wrote that they could see Mount St. Helens in the distance.
Mount St. Helens is the youngest and most active of the Cascade volcanoes. Since the last ice age, it has erupted more than forty times. After a minor eruption in 1857, the volcano fell silent. That all changed on this date in 1980. Mount St. Helens erupted catastrophically, causing massive destruction. Fifty-seven people died, and homes and businesses were destroyed.
The destruction did not remain local. The volcano blasted an ash cloud twelve miles into the atmosphere. Some 540 million tons of ash fell across twenty-two thousand square miles. Most of it fell over Washington and Oregon, collapsing roofs, closing roads, and clogging rivers. But the ash did not stay there. Winds carried it east across the Great Plains. The ash drifted over Idaho, Montana, North Dakota, and into Minnesota.
By the time the ash cloud reached North Dakota, it was much lighter. The ash settled over agricultural fields and produced some surprising results. Crops close to the volcano were buried under heavy ash and were a total loss. In North Dakota, however, the lighter layer proved beneficial. Thin coverings of ash helped retain water, added nutrients to the soil, and reduced insects that damage crops. For all the devastation caused by Mount St. Helens, North Dakota got off lucky.
Dakota Datebook written by Dr. Carole Butcher
Sources:
- All Quakes. “Recent Earthquakes in North Dakota.” https://allquakes.com/earthquakes/north-dakota.htmlAccessed 4/20/2026.
- All Quakes. “Latest Quakes in California.” https://allquakes.com/earthquakes/northern-california.htmlAccessed 4/20/2026.
- National Parks Service. “Phantom Volcano in South Dakota.” https://www.nps.gov/articles/phantom-volcano-in-south-dakota.htmAccessed 4/20/2026.
- United States Geologic Service. “The Volcanoes of Lewis and Clark.” https://volcanoes.usgs.gov/observatories/cvo/Historical/LewisClark/volcanoes_lewis_clark.shtmlAccessed 4/20/2026.
- Lewis and Clark Journals. “November 25 1805.” https://volcanoes.usgs.gov/observatories/cvo/Historical/LewisClark/volcanoes_lewis_clark.shtmlAccessed 4/20/2026.
- Britannica. “Eruptive History.” https://www.britannica.com/place/Mount-Saint-HelensAccessed 4/20/2026.
