US 26 from Moran to Dubois

Jdwilfert, great to get info on routes but a good Truckers Atlas will be at your fingertips and you can then plan your trip with confidence. You will find that what is a good road and what is not depends on the driving skill of the driver and his confidence in his skills.

That's a perfectly good route. We are not a 45' coach towing, but are towing a 35', 13k FW and we've taken that route several times without problem. Togotwee Pass is a slow gradual uphill climb and back down again, but very do-able.

There are various videos online showing the route:

Thermopolis to Cody - in reverse - Thermopolis to Cody

Togotwee Pass from Dubois to the top

Section of Riverton to Thermopolis through the Wind River Canyon

Between Moran and Dubois, you will cross a pass, but it is not bad at all..although it might have some construction going on...it's that time of year.
But it's a pretty route. And north of Riverton, you go through a canyon on the Wind River, a gentle climb, no bad curves, etc. And once past Thermopolis.. a state park there with hot springs... it's fairly flat to rolling hills.

But there's nothing wrong about going through Yellowstone and out over the pass..