The U.S. Geological Survey assigned threat levels to all U.S. volcanoes - of the 18 most dangerous, 10 are in the Pacific Northwest.
Jamie Hale | The Oregonian/OregonLive, Portland Oregonian: Travel
Tue, 01/09/2018 - 7:15am
The U.S. Geological Survey assigned threat levels to all U.S. volcanoes - of the 18 most dangerous, 10 are in the Pacific Northwest.