Formation over Crested Butte, CO

The report, as filed

Mid-day sighting against blue skies. Roughly 20 white objects in a pretty tight formation, with one in lead at center of line which was parallel to the horizon to start. No rumble, roar, or any noise we could associate with the grouping. I was working at about 10,400' in Crested Butte, CO and the formation was several thousand feet above us (two other witnesses in my immediate company). All facing South, I estimate our viewing angle never rose above 70 degrees, starting at 0-5 degrees to our Western horizon. Visual contact started just over the Maroon Bells and was maintained until it passed in front of the Sun, where we all lost it within a few seconds of each other. Looked roughly like this if against a horizon you are facing dead-on “........:........” The distance covered from where contact started to where we lost it against the sun, at our altitude, is over 7 miles, and again these were several thousand feet above us. I had to research tundra swans after the sighting to see the altitude and speeds they fly at even in jet streams and I couldn't find any flocking birds that would be that high in our area. The entire sighting lasted 90 seconds to 3minutes max. We all remarked that the formation was moving at jet-speeds but I have no recollection of their speed changing or stopping at all. Stayed constant. The ones in back behind “the leader” were all sort of jockeying for position, though. They made only lateral moves to either side and they did it throughout the sighting. No”hitting the brakes” and swooping around from behind. They were all staying in line but sort of hopping over one another to their port-starboard, back and forth. Very strange. I have followed the “Colorado drone swarm” story and know satellites cause a lot of confusion but this was midday and these were well above over the counter drone heights that match other reports even the FAA conclusion. Hoping someone has some ideas about it because I'm still perplexed but lean towards drones.

Held as-reported from National UFO Reporting Center (record NUFORC #159269). Witness text is preserved verbatim, including its spelling; nothing is edited beyond formatting.