1) I was in a work truck on a place called Calamity Ridge between Rangely and Meeker, CO.2) Looked at the horizon while I was driving.3) I thought it was a jet contrail.4) It wasn't an object. Just a visual anomaly that I can't explain. I couldn't tell if it was a jet that had crashed or if something had been propelled into the sky. It had to have been 100 miles away, but nothing ever appeared in the news.5) I was just baffled and confused. I thought someone else could explain it to me, so I took two pictures. I've asked a few people in aviation and astronomy, but they can't seem to figure it out either.6) The contrail/shadow simply dissipated within minutes.