National Geographic

On May 18, 1980, Mount St. Helens in Washington State erupted in the most explosive volcanic event in U.S. history. Fifty-seven people and countless animals died, a forest was leveled, and ash blanketed the region as far away as Minnesota.

The volcano remains active today, even as events are being held at the mountain to mark the 36th anniversary of the disaster. Proving that it still has power, over the past few years, Mount St. Helens has had "a baby volcano growing in its crater," says Stephanie Grocke, a volcanologist at the Smithsonian Institution and a National Geographic explorer.

Between 2004 and 2008, enough molten rock oozed out of the crater to pave a seven-lane highway from New York City to Portland, Oregon, notes Grocke. While the growth of the lava dome doesn't mean there is an imminent threat, it is a reminder that Mount St. Helens is still very much alive.

"The volcano is still living and breathing," says Grocke.

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Additional footage provided by the USGS.

PRODUCER/EDITOR: Laurence Alexander
SERIES PRODUCER: Christopher Mattle Show less