You MUST see the
Grand Canyon in Arizona. It has got to be the greatest natural wonder on Earth that anyone can see without being an athlete or mountain climber. Get a reservation at the
El Tovar hotel at the Grand Canyon Village and if you get one of the two bigger suites there you can take in the canyon from your own balcony.
From there you should also see
Meteor Crater which is about a two hour's drive from the Grand Canyon Village. It's not as awesome as the canyon but it too takes one's breath away seeing the power of nature. Once you've had your fill of seeing the biggest holes in the ground
you can then go to Las Vegas which is about half a day's drive from both places. In fact what I do is first go to Vegas and from there see the other two. Vegas is its own wonder. That should sop up about a week right there.
You can even go on arranged tours to both from Vegas.
Just FYI I live in Florida and live nowhere near these places just to show I don't have an axe to grind.