In the words of the family who filmed it, "while feeding our cows on a very cold evening on our farm and ranch north of Lambert, Montana, my husband and I noticed a black ring floating in the sky. Had we not known it was a smoke ring that came from one of the oil wells over the hill, we would have thought we were being visited by aliens! This smoke ring was caused by an oil well worker that was blowing out the regulator in oil well flare. The cold, still air provided the right environment for the exhaust to make this smoke ring. The ring stayed intact for several minutes before breaking up and dissipating."
The total lack of wind and the cold air produced some amazing effects here - in fact, we're not convinced. Could it all be part of a coverup, and there are really little green men behind it? Or could it be that Bigfoot was sending up smoke signals from some unseen hideout?
You decide, but remember: the truth is out there!