One of my many, many on and off road dream routes in Colorado

           One of my many, many on and off road dream routes in Colorado 
(There are sooo many in CO!!)

Gold Belt Scenic Byway – AKA Shelf Road and its siblings!
Gold Belt Scenic Byway is a journey through Colorado’s former mining country. It offers breathtaking scenery that you won't find anywhere else. It is located in southern Colorado and is 131-mile long.  Some parts of the route are, naturally, unpaved.  Along the way, there are many abandoned mines, buildings, and cool ghost towns.  There are lots of viewpoints and stops for great photo ops.  The road offers top notch scenery and views - but beware as some portions are particularly unforgiving with the roads are narrow and rugged in places.

The byway contains many roads (below info taken from greatest roads website):
Phantom Canyon Road: It connects CaƱon City and Victor through Phantom Canyon. It features one-way tunnels, narrow gaps and a red curved bridge to master. The road has two tunnels and three elevated bridges. It is unpaved.
Shelf Road: It goes through Fourmile Canyon. It is carved along the side of a cliff that is supposed to fit two lanes, but really only fits one.
High Park Road: It is entirely paved and connects gold mines with the Arkansas Valley.
Teller County Road 1: It is paved and offers diverse views of scenery.
Gold Camp Road: It follows the former railroad from Colorado Springs to Cripple Creek. The road opened in 1920’s. It’s gravel. The road is said to be severely haunted.

And I would also throw in this pass - Douglas Pass is a high mountain pass also referred to as State Highway 139, aka Douglas Pass Road. It has several switchbacks and is quite narrow in places. The pass is located between the towns of Loma and Rangely.