I am sitting here in SC at the site of one of the heaviest EQs west of the Mississippi in recorded history.
However, nothing can eclipse the Great Madrid EQ of 1811-1812. That was a humdinger - and a testament to the EQ that occurred on the run-up to the visit by the Savior to the New World and His sheep here (one fold, one Shepherd for those who are not LDS).
My point in sharing this is to point out that N. America is slowly being torn apart. One day, it will accelerate catastrophically, as pointed out in Visions of Glory. The Mississippi will no longer be crossable, but will become a gulf which stretches from New Orleans to Montreal. If you can read land forms; this is reality.