Kathy,
I assume you are coming for the changing aspen season. Kebler Pass has incredible aspen stands for many miles from Crested Butte until you drop off the high meadow elevation and into Paonia along Anthracite Creek. Lost Lake is one of my favorite areas, as well as Ohio Pass, a different direction, that goes into Gunnison. Roads are gravel graded and should be accessible to 2WD if there is no snow.
We live on the western slope near Cortez, Colorado and the San Juans are also spectacular in the fall. Dallas Divide is very popular and has pull offs to view Sneffels one of the great, "vista views" in the state.
The Wilsons are beautiful near Telluride if you get that far over. You may choose to head into Ouray and down the "Million-Dollar-Highway" to Durango. This road has three mountain passes, Coal Bank, Molas and Red Mountain. It takes awhile but as you expect, incredible views. All paved roads
I've been on the train at least a half-dozen times. It follows the Animas River into Silverton and then back down the same route. It can get tedious both ways and you can option to take a bus back to Durango but you will save no time. It takes a full day. They offer a photographers trip in Sept. or Oct. and it will be full of shooters.
If you head east from Durango and through Pagosa Springs, over Wolf Creek Pass you'll come to South Fork. Turning back toward the north on 149 you could visit Creede or farther on drive over Slumgullion Pass into Lake City, or as the locals know it, "Little Texas". Paved
Just south of Lake City coming down Slumgullion Pass are views of Uncompaghre and a pull off for Lake San Cristobal, both great views. Paved
If you go over to the sand dunes you will see Blanca Peak east of Alamosa with the Sangre De Christo's to the north of the dunes.
Enjoy your trip.
