Sky Quakes, Broken Gear, or Something Else.

[l0st]

Good thought, I wonder if all those different regions would have the same issues though. Washington State but not Oregon. California and Neveda but not Arizona. Montana is a real out layer given the Idaho wasn't affected. 

Still your idea is currently as good as any at this point.

Much of Cali and Nevada are below sea level. I'm not sure about Arizona, though. What Maxmars posted would make sense in the context of those states.  Can't say I know too much about the terrain in Montana and Idaho either, except for potato and corn fields... and fly fishing in "A River Runs Through It" - great movie.