some great roads already mentioned. @gogriz91, I'm sure you are talking about southwestern CO, met up with 30 of my closest friends for a 4 day excursion on many of the roads you mention, Pagosa Springs, Our, Durango, Silverton, great great stuff.
@flatbutt mentioned the WV routes I've done a bunch of times, September is a great time to be there, leaves changing, great weather, cool but no snow yet at elevation.....most of the region has no cell service or any other radio activity to speak of...due to the National radio quiet zone and the green bank observatory.
https://en.wikipedia.org/wiki/United_States_National_Radio_Quiet_Zone --this makes it a challenging place to get help in case of a breakdown or worse.
the northeast has some great roads, too, if you escape the metropolitan areas. I frequent Mount Washington, and love the Kancamagus Pass, but you really can't go wrong up there as long as you avoid the frost heaves in the early spring and the tourist season in the summer