I Was sitting at k-mart here in Sheridan, Wyoming looking at a large dark blue bank of clouds east of me when I noticed a cage like structure flying along side of the cloud. It had to be big in size because Cloud was about 15 miles from me and UFO was about a quarter inch long and an eighth inch wide. I could see the cloud through the cage bar structure. UFO was moving from north to south fast as a fighter jet along the cloud then flew into the cloud and vanished. This was about 8:15 PM . 07-03-2016. UFO sighting lasted10 seconds at the most.