I think we have a winner here:

"Strange happenings in our skies
A little before 9:30pm tonight I heard the sound of an approaching helicopter and went out on my deck to check it out. I saw it approaching from the southwest and it was heading northeast. As it was flying past a little to the west of my house on Bow Mountain Rd, I saw it deploy what I suspect was a drone. As the helicopter flew on, it deployed a second, and finally a third. They hovered in place for a short while. Once the helicopter was gone, there was no sound whatsoever from these objects. I watched for a while as the first and third object flew east and the second headed west. The third craft flew directly over my house but no sound was heard.

This was very strange. Did anyone else happen to see this or know what this might be? I'd really like to know."

FYI this is a bit west of the north end of Boulder in the foothills.