First BIG trip coming up

[Pugpen]

We bought our first TT at the end of January. We have camped out on our property several times to familiarize ourselves with everything and to make sure we have what we need. We have also done two nights at a local park.
We will be traveling from Arizona to Mt. Rushmore, then threw Wyoming to Priest Lake in Idaho. then back down to Arizona. My question is for anyone familiar with I25 going from New Mexico to Wyoming. What is the interstate like? Steep grades? Desolation? I have looked at our route with Google earth and it looks so baron. I am from originally from Northern Virginia and use to seeing civilization. I am still not use to being out west where one sees nothing for miles and miles.
We have plotted our trip so we will be driving no more than 300 miles a day and staying at state parks on our way up to South Dakota. With a few days at each stop. It has always been our dream to travel like this once we retired. Now that it is here, I am surprised at my concern for the unknown. I hope once we get on the road it will quickly disappear.
Thanks for any input!