Months before Mount Saint Helens erupted, scientists observed earthquakes, gas releases, and a growing bulge on the ...

On the flanks of Washington State Mount Rainier, a spike in seismic rumbling has revived an old, unsettling question for the ...

After a year of explosive episodes, the summit continues inflating with fountaining possible as early as Wednesday.

A big, messy surprise greeted Yellowstone National Park early Saturday morning, just as winter officially began. At around ...