Officials are tracking the largest swarm of earthquakes in more than 15 years on Washington's Mount Rainier but say there is no indication that the cluster of quakes is cause for concern.The U.S. Geological Survey Cascades Volcano Observatory said the swarm began early Tuesday at the 14,

Mount Rainier is considered an active volcano and has not had a significant eruption in the past 500 years. However, it is potentially the most dangerous volcano in the Cascade Range due to its height, active hydrothermal system, frequent earthquakes, and heavy glacier cover.