Wasatch Fault zone.

It is over 800 miles long, stretching from Arizona to Montana.
It is an active earthquake zone that has have shaken Utah
every 300-500 years with quakes estimated upto 7.5 on Richter
Scale and vertical ground displacement upto 8-10 feet according
to the Utah Geological Survey, which has a youtube video
explaining all of this and more.
Since there has been no major earthquake along this fault since
the first Mormon colonization of Utah territory about 150 years ago,
and geologic records along the fault indicate that no major quake
has taken place in 300-400 years, Uah maybe maybe maybe OVERDUE
for a major shake; one that could bring havoc to Salt Lake City, etc.,
I advise Utah habitable-zoners to seek out earthquake survival
websites for valuable info.

BTW, since the Wasatch fault develops major quakes every 300-500
years, it's amazing, almost miraculous that those 20 million year old
natural 'stone bridges' in Utah have survived so long.