1980 - Mount St. Helens Eruption
May 18, 1980 started out peaceful for most of the country. But in eastern Washington, seismic activity reached the eruption point literally. Mount St. Helens, dormant since 1857, became active a couple months earlier in March. Geologists focused on the north face where a bulge could be seen growing. There had been small eruptions leading up to May 18th, but nothing measured the same level as the eruption on that Sunday. At 8:32 am (Pacific time), Mount St. Helens erupted blowing down or burying 230 square miles of forest and shooting ash thousands of feet into the air. Fifty-seven people were killed and the ecosystem on the mountain destroyed.
In the nearly 30 years since the eruption, the USGS has studied the eruption and many of its reports are available online. In 1982, the Mount St. Helens National Volcanic Monument was created as an education, research, and recreation center.