In Bill Bryson's book, A Short History of Nearly Everything, he talks about the dangers of Yellowstone and how catastrophic the eruption would be, however, he also points out that these potential eruptions are often preceded by a period of elevated signs of volcanic activity, which as I understand, Yellowstone is not currently experiencing. Of course, geological timelines are impossible to predict, but until I read that book, I didn't even know Yellowstone was dangerous and wouldn't have found out until reading this article.