The Dinosaur Scenic By Way road (Hwy 139) from Grand Junction to Rangely is an old style pass with tight switch-backs and the heart of Douglas Pass has a strong grade. Currently, 139 on the south side of the pass has some pretty healthy pot holes and dips. Our Scamper will travel this road often in the future. 

All that said it is a beautiful drive, with the possibility of seeing brown bears, elk, (depending on time of the year), deer, almost always, and wild horses quite often.  Golden eagles, and bald eagles sometimes are seen. 

The only other tricky part of the diamond drive is 128 from just north of Moab, Ut back north-east to Interstate 70.  The road along the Colorado river is FABULOUS, but narrow. At times there is rock wall on one side of the road and river on the other with no shoulder at all.  This is fine if there is not a biking event.  Check to see if there is an event on the road as sometimes it is closed, or like last Sunday (March 11, 2018) when there were hundreds of bicyclists and it was very chaotic as riders were headed in both directions. The road is undulating and curving with many places with no long view ahead, making passing interesting. But, it is a not to be missed drive.

This is my home area, so if there are specific questions I will do my best to answer.

Here is a site about the drive. http://dinosaurdiamond.net/