There is a 16 percent probability of a volcanic eruption in California in the next 30 years, according to a new report from the United State Geological Survey and state officials.
The report examined eight volcanic zones ranging from a "moderate" to a "very high threat" of blowing, the report said.
Mount Shasta, Clear Lake volcanic field and Medicine Lake volcano are among the volcanoes deemed to be a high threat.
There are 200,000 people residing in the so-called hazard zones found near the volcanoes.
"Eruptions occur in the state about as frequently as the largest earthquakes on the San Andreas fault," said USGS Regional Director. Mark Sogge.
In October, Northern California's Mount Shasta ranked among the five volcanoes in the United States that were most likely to erupt.
Unlike earthquakes, there is a network of sophisticated sensors that can detect volcanic precursors like increases in seismic activity and gas emissions.
Besides the cities and towns near the most highlighted volcanoes, major highways, like the I-5 from Redding to Oregon or recreational areas such as Yosemite, Lassen and Shasta-Trinity could be affected.
"Understanding the hazards and identifying what and who is in harm’s way is the first step in mitigating volcanic risk and building community resilience to volcanic hazards," the report said.
Lassen Peak was the most recent California eruption, showing activity from 1914 to 1917.