John knows the area, that's for sure. He was my RV-1 escort pilot from Twin Falls to Winnemucca last year. In Foreflight, I just put in Indy to Medford (guessing your start-stop spots), and the great circle is a pretty good route. It supports going the I-80 route from Cheyenne to Salt Lake City (actually a bit north of each), and then N of I-80 towards Medford. Its N of the CO Rockies, and S of the Tetons...not a bad way to go, weather permitting.
For that RV-1 trip, we flew this route:
Toledo, OH - Elkhart, IN - Peoria, IL - Lees Summit, MO - Colby, KS - Broomfield, CO - Rawlins, WY - Rock Springs, WY - Ogden, UT - Twin Falls, ID - Winnemucca, NV - Reno-Stead, NV.
The most direct route for you would be a bit north of that, but offers a lot of good stopping spots. I'd probably bee line it for the Cheyenne area, picking cheap gas spots along the way (which would not include Cheyenne...but somewhere nearby for better gas $). Then along 80 to Logan or Brigham City UT, or Preston, ID (good gas stops that keep you a bit north of SLC, which helps you avoid the restricted areas W of SLC with little or no deviation). Then head direct S Oregon, picking more good gas stops. Gets a little sparse as you slide N of 80, but the terrain is friendly, and there are stops. If you have time, swing by Reno-Stead and visit...a bit out of your way, but I'll show ya some cool planes, and swap rides with ya!
If the weather is good, just before SLC, you can make a foray up to Jackson and see the Tetons and Yellowstone (its just a bit N of the great circle route, and is where John was referring to).
Just saw Bob Ax's post, and we're talking about the same route.
Put the word out where you'll be stopping, and I'll bet ya a lot of folks come out to see ya...lots of RVs along that route! Have fun Randy!
Cheers,
Bob