The desert covers over 3.3 million square miles, which means it's roughly the same size as the entire United States.

Another nearby volcano that erupted in 2009, Mount Readout, showed volcanic tremor for two months before it blew its top. "If we see [tremor]," Haney said, "that will be the next sign that Spurr ...

Mount Spurr, located about 75 miles West of Anchorage, has been acting up in recent weeks, prompting officials at the U.S. Geological Survey and Alaska Volcano Observatory to issue a yellow alert.

Elevated levels of volcanic gas and earthquakes have been recorded at the site. Alaska's Mount Spurr, an active volcano near the most populated region in the state, is getting even closer to an ...