Do you remember?

Sort of a man vs. nature thriller. Here is my idea.
Did you know that one of the largest active volcanoes on earth is pretty much all of Yellowstone national park? It’s true! (Here is the wikipedia entry on super volcanos) This is what causes Yellowstone to be such an amazing place.
Last time it blew, it blanketed everything west of the Mississippi under several FEET of ash. The volcano is still active, and it blows, on average, every 600,000 years. It last erupted about 600,000 years ago.
I want to write a story starting with that event. It’ll follow two groups of people for a few months, and will be filled with interesting events like the earthquakes the eruption will cause, massive fires, the effect of ash inhalation, the distruction of our environment, and other terrible things. It will NOT have a happy ending.
What do you think?