Definitely Kebler Pass. It is part of the West Elk scenic loop which is something like 150 miles total. Kebler Pass is unpaved but rideable on a road bike. The loop travels along the top of the Black Canyon of the Gunnison and is one of the most scenic in the state. I suggest riding from Crested Butte, over Kebler Pass, Paonia, Hotchkiss, Crawford and get somebody to pick you up at the Blue Mesa Dam. Probably a little over 100 miles with maybe 7000 feet of climbing - an epic day for sure!