Orange and red blinking triangle over a state park, where I was taking photographs.Went up to Hyalite Reservoir at night to take some Astrophotography. I was taking photos when I saw it show up on my screen after I took the photo. The photo is a long exposure, you can see it streak across the Sky but that's it. The object slowly flew over the reservoir and toward the mountains where it disappeared over the ridge. It had 3 orange/red lights that formed a pointed triangle, with all 3 emitting a slow blinking red light too. My locations was out in the middle of deep mountains of a state park and I've never once seen a plane fly near it.((NUFORC Note: Witness elects to remain totally anonymous; provides little contact information. PD))