After noticing a bright light in the sky, I watched it for a while until it vanished.I was driving Westbound on Interstate 70 about 30 miles West of Limon Colorado. It was about 4:00pm MST. The sun was to my left and starting to set. This portion of I-70 runs from the Southeast to the Northwest (where it jogs north before going into Denver heading West). I noticed a bright light to my front right, (looking through the front windsheild) it was fairly high in the sky. The brightness seemed to me to be from reflecting the sun, it was very bright. I couldn't dicern a shape. After about 30 seconds or so, it disappeared. I know this isn't much of a report. I thought I'd report it in case anyone else in the vicinity saw anything similar...