Looked up in the dimming night sky--sun was still setting--orange to the west---above I saw a very bright -very large STRAIGHT object

(I am vacationing in Laramie, Wyoming when this occurred) On the evening of July 15th around 8pm, I looked up into the sky (above) and noticed a HUGE BRIGHT LIGHT--It was shaped like a I. (Like a line in the sky).I thought it was the moon--because it was so bright, but it was only an object (stationary) in the sky--to my eyes, it was shaped like an I. thats what it looked like, a very bright, very large I in the sky. I watched it for about 30 minutes, my adult daughter saw it as well from a different area of town. It completely disappeared after about 30 minutes. Just vanished.