Mount Rainier is an active stratovolcano 45 miles southeast of Tacoma and 60 miles south-southeast of Seattle. Its last eruption was "a light dusting of ash" in 1894, the USGS said in a report. Large eruptions haven't occurred for more than 1,000 years.

A swarm of hundreds of small earthquakes have been detected rumbling deep below Mt. Rainier in Washington State early Tuesday morning, though geologists stress there is no cause for concern.

One of the most famous mountains in Washington, Mount Rainier, has been rumbling over the last day due to the amplified seismic activity. (Representational Image) Seismic activity at Mount Rainier has surged, with the largest earthquake swarm since 2009 ...