They moved very slowly in a triangular formation across the sky then disappeared one at a time. We were in Lafayette, CO in my cousin’s backyard facing west. The lights appeared to be approximately 3000-6000 feet high, coming from the West-Southwest and moving to the southeast. When they disappeared, they seemed to be directly over Denver. I was only visiting on my vacation, so I am not positive about the exact location or direction we were facing, but I am sure we were looking towards the west. We viewed the lights for approximately 15-20 minutes before they disappeared.
Source and author: alexlankhorst (youtube)