This was something they brought up on the discovery channel. I don't remember all of it, but I do remember them saying that the earthquakes would be the start of the eruption. Not only will they become frequent, but that they believe it will be some of the biggest quakes ever recorded.
I would assume those would be not only felt here, but also extend through the fault lines to reach the massive, but dormant, fault line that runs through the midwest.
I know it's all hollywood, but I recommend watching the movie 10.5 and the sequel to that movie. The events are based on real worst case scenario models, although taken to the extreme with HollyBS magic. Never the less, that is the kinds of devastation we could be looking at. The movie does fail to take into account Yellowstone. Any significant quake could be the event needed to rupture Yellowstone. Best case scenario would be the cauldron just leaked the lava into new or existing fault lines, draining the cauldron enough to make it less of a threat. Obviously the worst case scenario, would be bad.
This is all speculation of course, but it's what I've read about and seen on discovery.
The earthquake area I was talking about was here in the midwest - the Madras Fault. (sp)
Would it work the other way? Could an eruption at Yellowstone trigger a quake here? (After all there are small quakes there already. And if there was enough lava escaping would that cause a collaps (or earth movement) THERE enough to shake (or move) our area?
Did that make sense at all? ^
(BTW; I did see both 10.5 and sequal. Wouldn't that be a mess?!!)