Glad to help.
Here is the route I would recommend when heading to Vegas...Google says it will add about 2 hours. Probably less though. Watch your speed through AZ...they are tough on speeders. In CO, you'll see local and troopers here and there, but common sense should keep you out of Trouble. US 550 is called the Million Dollar Highway.
You also have a couple of National Parks on this route if you want to check those out.
https://www.google.com/maps/dir/Colo...36.1699412!3e0