You may or may not have visited Yellowstone National Park. You may not even know that it is located in Wyoming, Montana, and Idaho. But that big, original western national park may be in your face one of these days soon. Talk about the Big One in California, the giant earthquake. That would be nothing compared to what Yellowstone may do one of these days.
The first national park is also a dormant, giant, super volcano. Nobody knows what the trigger is to get it to explode big time. We do know that it would not be one of those cone volcanoes so familiar from Hawaii where molten lava streaks down a mountain slope. This would be far uglier and would resemble Mount Vesuvius blowing its lid in 79AD in Roman times during the Emperorship of Titus. Ash would spew out in all directions and cover the landscape for hundreds of miles. Nothing would grow. Cities would get buried. Nobody could live there anymore.
In short, the Yellowstone volcano could bring an end to the civilization of the US just as it cut a swath through ancient Rome. Read more about it in the upcoming alternative history thriller, the Old Faithful Plot, coming soon from Cheops Books. LLC.