2012 Ford Fusion, is it safe to travel over mountains?

Looking to travel to the Grand Canyon, I'm located in Indiana, my car is a 2912 Ford Fusion, and I was curious if it would be safe to take it there

I don't see the problem… They probably have good roads there… Make sure you have a spare tire.

Of course it is safe as long as the car is running as it should.

You'll be fine but a spare tires always a good idea when going long distance or at least a can of fix a flat

Of course, why would it not be?

Yes it will be fine. Air is thin at altitude but ecu and sensors will adjust and keep it running though you may find power drops off until we return to sea level. Hot dry air also causes reduction in power output. Roads are mixed and some decent others a real nightmare. The real worry is the very poor driving over there.
be cautious. Have breakdown kit. Even spare water! Check car and have serviced at least 2 weeks before going. Thus any issues from servicing ( loose HT lead?) can be sorted. Mobile phone is useful but signals vary a lot too.