The last large earthquake swarm at Mount Rainier occurred in 2009 and lasted for three days. The swarm resulted in more than 1,000 earthquakes and the largest was of a 2.3 magnitude, according to ...

The snowcapped peak of Mount Rainier, which towers 4.3 kilometers (2.7 miles) above sea level in Washington state, has not produced a significant volcanic eruption in the past 1,000 years.

The hundreds of Mount Rainier earthquakes detected Tuesday marked the largest seismic swarm at the active stratovolcano since 2009, the USGS said.