sounds like you've covered some good ones on this side of the state, but IMO you'll have to travel to the S.W. corner to find the best of the best in this state. Hwy. 141, the Gateway canyon, which a good portion just got repaved, is probably my favorite twisty in the state. Followed closely by Hwy. 92, black canyon to Hwy. 50 is pretty awesome. Also in that corner is Hwy. 65, the Grand Mesa, which is pretty darn fun too. Probably should also mention the Million Dollar hwy. out of Uoray too, although traffic can often times be a PITA. And Hwy. 149 from Hwy. 50 to Hwy. 160 is pretty good too. All of those have much less traffic then any of the twisties on this side of the divide.
Unfortunately those are all over your "3-4- hours away" criteria.
1987 Yamaha Venture to 88,256 miles...crashed
2009 FJR 33750 miles and counting