Mount St. Helens, Before the Blast
Mount St. Helens looks serene in a photograph taken from the shores of Spirit Lake in Washington State in 1973—a few years before the volcano's infamous 1980 eruption.
Today marks the 30th anniversary of the blast, which killed 57 people and leveled hundreds of square miles of pristine old-growth forest.
"The eruption really caused drastic changes in the forest ecosystem," said Mark Swanson, a forest ecologist at Washington State University.
Before the eruption, the dense forest cover meant there was little light and low wind speeds in the area. But afterward, Swanson said, "you had a very open system ... with a layer of volcanic ash over most of it, varying in depth from hundreds of meters to just a few inches."
MORE MOUNT ST. HELENS COVERAGE
• Mount St. Helens Still Highly Dangerous, 30 Years Later
• Mount St. Helens Pictures: 30 Years Later
• Mount St. Helens Interactive: Rebirth of the Blast Zone
• "Mountain With a Death Wish" (1981 National Geographic Magazine Article)
• Pictures: America's Ten Most Dangerous Volcanoes
• Mount St. Helens May Erupt for Decades, Scientists Suggest (2007)