The U.S. Geological Survey has updated its threat assessments of the 161 active volcanoes in the United States, ranking 18 of them as a "very high threat" because of what's been happening inside them and their proximity to people.

Yellowstone National Park's volcano ranks as a "high threat," but you still have more to fear from tourons -- tourist-morons -- harassing bison than being incinerated by 2,000-degree lava erupting in your cabin.

The U.S.G.S's volcano update is the first since 2005. The danger list is topped by Hawaii's Kilauea, which has been erupting this year. The others in the top five are Mount St. Helens and Mount Rainier in Washington, Redoubt Volcano in Alaska and Mount Shasta in California.

The agency says a dozen volcanoes have risen in threat level, while 20 others have declined in threat level.

Among those where the threat score ranked higher are Alaska's Redoubt, Mount Okmok, Akutan Island and Mount Spurr volcanoes. Threat scores also rose for Oregon's Newberry Volcano and Wyoming's Yellowstone.

The U.S. Geological Survey's updated report named 18 very high threat, 39 high threat, 49 moderate threat, 34 low threat, and 21 very low threat volcanoes.

Yellowstone ranks No. 21, as a high (but not very high) threat volcano.

"The threat ranking is not an indication of which volcano will erupt next," the report said. "Rather, it indicates how severe the impacts might be from future eruptions at any given volcano"

The major eruption in Yellowstone 640,000 years ago created the 1,500-square-mile caldera that is home to the park's famous thermal features that are continually powered by the thousands of cubic miles of magma that circulate underground.

An eruption 2.1 million years ago—among the largest volcanic eruptions known -- ejected as much as 6,000 times the volume of material ejected during the 1980 eruption of Mount St. Helens in Washington.

Meanwhile, the Yellowstone National Park's website about the volcano said there's nothing to worry about, for now.

"Another caldera-forming eruption is theoretically possible, but it is very unlikely in the next thousand or even 10,000 years," according to the website. "Scientists have also found no indication of an imminent smaller eruption of lava in more than 30 years of monitoring."

So go ahead and plan your visit.

And don't feed the bears or pet the bison, or tolerate those who do.