"They ain't done yet," says Steve Malone, a longtime researcher of Cascade volcanoes. And of the 13 major volcanoes that stretch from the Canadian border down to Northern California, many geologists agree that Mount Rainier poses the greatest threat. Here's why.
Geologists: Glacier Peak One of Washington's Most Dangerous Volcanoes
The remote mountain is also one of the Cascades' least-monitored volcanoes.