[D-fendr]

I would say less than half a mile before they simply got so thin they no longer looked like a contrail at all.

Must be a local Denver phenomenon. A quarter of the sky or more is not unusual around here and elswhere:

[TigersEye]

Show me an example then instead of that pic. The widest contrail in that pic is not a mile wide and, more to the point, it is very thin and wispy. It bears no comparison with the contrail in the video does it?