Why Mount Rainier is the U.S. volcano keeping scientists up at night

The snowcapped peak of Mount Rainier, which towers 4.3 kilometres (2.7 miles) above sea level in Washington state, has not produced a significant volcanic eruption in the past 1,000 years. Yet, more than Hawaii’s bubbling lava fields or Yellowstone’s sprawling supervolcano, it’s Mount Rainier that has many U.S. volcanologists worried.