Don't know if this helps, but there is camping south of there, in Encampment/Riverside, and also up a few miles on 130 (left on 130 instead of straight on 230). By the way, the trip up to the top of that pass is gorgeous.

I don't remember seeing anything between there and Rawlins, but I wasn't looking, so that's pretty meaningless.

Also, the city park in Walden allows camping, and there is a rec center/pool with showers you can buy for a small fee. Watch where you set up your tent, though, they water the lawn at night.

Also, when I went through there in 2003, there was a couple who ran a bike-hostel just north of Dubois, and that was a really friendly and nice place to stay.

Have a great trip.