I can't really speak for Colorado as I have not traveled there very much, but don't underestimate the roads in the Appalachians/Smoky Mountains. Some get very narrow and curvy.
Do your research on your route with the trailer before hand. A few years ago we were traveling in our car and just plugged in the address to Bryson City, NC in the GPS and took off from Houston, TX. We ended up on a road outside of Bryson for about 50 miles that was about the narrowest and most curvy road I have ever been on. Was a blast in my car, but would have been a nightmare in my truck and trailer.
