A river channel filled with cliff swallow holes carved into the Desert Spring Tuff. Image by Erik Klemetti

Earlier this month, I spent a little over a week exploring one of the biggest mysteries in then Cascade Range. These volcanoes span from Northern California into British Columbia and host such well-known peaks as Mount St. Helens, Hood and Shasta. Yet, some of the largest eruptions over the past million years in the Cascades may have come from volcanoes that are totally hidden from view