South Carolina to Wyoming to Arizona to South Carolina

[Prilla]

I am so excited to find this forum. My family and I are going on an epic adventure odyssey :) in the last of August/first of September. We will be traveling from South Carolina to Yellowstone to the Petrified Forest in Arizona then back to South Carolina. If you plug those destinations into Google Maps you will see we will be making a big loop around the country. Our route is flexible, in that, we wouldn't mind driving a few extra miles (50-100) to see something really cool.

What are the must sees along the way?

What are some interesting locations to spend the night along the way?

My husband and I will be tag-teaming the driving. Would 800 miles a day be unreasonable?

Any and all suggestions and information is welcome!!!!

Thank you!!
Prilla