Black triangle above grand Teton maybe 2 miles wide corner to cornerMe and another person were sitting by campfire looking at stars. Noticed that there was a triangle section in the sky missing. It was pitch black where the craft was. We went and got 6 other people from the laundry area and asked what they saw. Same thing as we did. It was maybe 2 miles wide from corner to corner. It was there for 10 minutes. 30 minutes later in another section of the sky two shapes that looked cloudish came together in the moonlight and made a saucer shape. Then it proceeded to fly off. It was maybe couple miles wide a 10 miles away((NUFORC Note: Witness elects to remain totally anonymous; provides no contact information. PD))