Back in 2016 I took the entirety of CO 139 over Douglas Pass heading south towards I-70. I recently touched on CO 139 on my 2016 Mountain Trip blog series. I thought it was a cool highway if not a little haggard due to the obviously rural level of maintenance.
https://www.gribblenation.org/2019/03/2016-summer-mountain-trip-part-19.html