Mount St. Helens' last eruption ended in 2008 after the first series of eruptions began in 2004. Geologists recently recorded rising magma at the site of the volcano 2.5 to 5 miles beneath its surface, and it still remains active.

The volcano is famous for its eruption in 1980, which is known as the deadliest volcanic eruption in the history of the U.S., killing 57 people. The volcano was responsible for the destruction of 250 homes, 47 bridges, 15 miles of railways, and 185 miles of highway.

Geologists monitor the volcano's behavior through GPS telemetry and seismic systems in order to track carbon dioxide as well as thermal temperatures. Back in 2004, helicopter pilot Major Jeffrey R. Linscott flew over Mount. St. Helens and witnessed a deformation in the flanks of the volcano, which ultimately led to an eruption.

However, the current rising magma levels at the site do not indicate an imminent eruption, geologists say. Scientists at the Cascades Volcano Observatory and the Pacific Northwest Seismic Network have been tracking the volcano's behavior every since its deadly 1980 eruption. They've recorded similar "refueling" patterns during Mount St. Helens' quiet period in the '80s and '90s, so this recent magma rising isn't a revealing indicator for an eruption.

"This is giving long-term (data) that it's getting ready to erupt again, but it could be decades before it does something again," said Seth Moran, a volcano seismologist with the U.S. Geological Survey, in this CBS News article. "It's getting ready, but it's not there. It may stay perched at ready stage for a long time before it starts to erupt."

Past studies indicate that Mount St. Helens isn't likely to undergo a 1980-like volcanic blast for hundreds of years, but the refueling might indicate a smaller eruption, which could be an issue for those living near the volcano. We saw what happened earlier this month with Peru's most active volcano, Ubinas, which spewed ash into the air and forced villages to evacuate.

Geologists will keep tracking Mount St. Helens' behavior and continue to provide news. You can read more about it in this Christian Science Monitor article.