I did something similar. I wanted to avoid the Interstates and metro Denver, so I went to a location about halfway between Scottsbluff and Alliance. By taking CO 86, CO 71, and NE 71, as well as a few county roads, I got to travel through parts of Colorado I'd never seen before (I'd never been to Nebraska at all). I was also able to make the 560-mile round trip in less than 10 hours, including a little stop-and-go on the return trip between Kimball, NE and the south edge of the Pawnee Nat'l Grassland.

(The only annoying part of an otherwise enjoyable drive was during that stop-and-go. One driver, whose schedule was, apparently, far more important than everyone else's, decided to use the mostly-empty northbound lane as his personal express lane. He'd drive 50-100 yards, passing several vehicles, then hit the brakes and wedge himself into a too-small space when oncoming traffic became a problem. Of course, that caused a "braking ripple" through everyone who is now behind him.)