In 1999, while working a large fire in NE Oregon with almost 3 dozen other men. While we were setting up after arriving we saw an exact “Vee shaped” large dark craft with lights underneath. It appeared to be moving easterly, at appx 40,000′. It moved silently and steadily, no contrails or vapor trail. I watched it until it moved over the horizon. It all lasted about 3 minutes and we went about our job, but it had most if not all of our attention.
To this day, having grown up around USAF bases, including Edwards Flight Test Center (So, I have seen many prototype aircraft) I cannot explain what type craft, that large, moving in silence can be. Over 15 years now and still nothing like it on the news or anything close that isn’t classified a UFO.