My son Kamdin and I were coming across the Snake River heading north east on the bridge by Simplots when I saw a triangle shaped object hovering just above the Simplots plant. The object was dark gray/black. It was only a couple hundred feet above the plant so I could see all the detail in the bottom of the object. It made absolutely no sound and had no lights. It was about 7pm so the sun was already at the west horizon. So I could not see any lights. It slowly started moving northeast at a very very slow speed. We were on our way home which is only about half a mile from when we saw this object. Instead of turning left after the bridge to go home I stayed on the Burley Rupert highway and tried to follow it to get a longer better look. We were able to follow it almost 6 miles when it changed direction and went East where I could no longer keep up with it. I was very excited to follow this object and hoped I would be able to get closer but could not. After seeing this object I told anyone who would listen , especially some co-workers who have had their own sightings. One guy has had many and more interesting than mine. I have no sketch but could sketch what we saw if needed.