Specific roads
So .. this is long - but my back yard riding areas - so bear with me .....
After coming north out of Durango over the Million Dollar Hwy in to Ridgeway, go left / west on Colorado 62 to Colorado 145 to Norwood and then North on Colorado 141 through Gateway, CO. Stop in Gateway at the Gateway Auto Museum - it's awesome! Allow at least 2 hours there. The museum is the personal collection of the guy who owns all the Discovery Channels. Check it out here - gatewayautomuseum.com . CO 141 comes back around on to CO 50 - then you can go south (a bit boring through raw open desert - but not too far) back to your proposed route over to Montrose and the Black Canyon National Park ( take the road to the bottom for sure ). You can go all the way to Gunnison after the Black Canyon - or turn left on CO 92 and go over Black Mesa - one of the finest motorbike roads in the state - through Crawford (home of Joe Cocker) and on to Hotckiss, CO - stay west on CO 92 then north on CO 65 (scenic byway) over the Grand Mesa (cool on top usually - over 10k elevation) and then pick-em --- west on I-70 to get you back towards Grand Junction and the routes listed below through Loma, CO or east back to Rifle and your north route or further back to Glenwood to finish.
The other option after the Black Mesa (CO 92) is to go east on CO 133 through Paonia and the coal mine area over McLure pass past Marble, CO and around north to Carbondale putting you really close to Glenwood for the finish.
...or go north on 50 to Grand Junction after doing the Gateway, CO thing, west on I-70 for about a quick 15 miles (posted 75 mph) to Loma, CO (stop for fuel here! nothing on 139 until Rangely) and turn north on CO 139 over Douglas pass and on to Rangely, CO (fuel again)- then turn right on CO 64 east to Meeker and back on to your route up north on CO 13. FYI lots of oil field traffic, trucks and such on CO 13 going north out of Rifle to Meeker. If you have to take the Rifle to Meeker route, at least go through New Castle just west of Glenwood and up and around the "HogBack" and see Rifle Falls state park, Rifle Gap and Harvey Gap reservoirs the back way and end up on the north end of Rifle instead of the drone down I-70 at 75mph form Glenwood to Rifle. Or the reverse if coming from the north in to
Rifle - go east behind the "HogBack" in to New Castle then Glenwood. 3 times as long and a 20 times nicer ride.
Sorry this is confusing - way to many roads to list - and I just hit the highlights - pm me and I'll give you other ways to link all this together and places to eat (and avoid) and where to find fuel .......................