1980 Eruption Of Mount St. Helens

On May 18, 1980, a major volcanic eruption occurred at Mount St. Helens, a volcano located in Skamania County, in the U. S. state of Washington. The eruption was the most significant volcanic eruption to occur in the contiguous 48 U. S. states since the much smaller 1915 eruption of Lassen Peak in California.