Per John Bush request here are some video screen shots (from digitized VHS copy of Hi8 video - will try to get copies of original) of the rotary plowing in the dark just below and on Cumbres Pass.
Others may have better shots of the night time plowing, and I can probably get better screen shots off the digitized original if I can get my busy brother into action. Then a video copy would be better yet (request by PM)