"Snow Doughnuts"...anyone seen one?

Came across this article in the Seattle Times on snow doughnuts.

Anyone ever seen one of these?

Garth Ferber and I found one in the B.C. Coast Mountains a couple years ago. I don't recall ever seeing one before.

I've been thinking a little about snow donuts. It seems to me that they could only form two ways.

1) A snow wheel rolls down the slope and, at some point, the center falls out.

2) A small snowball starts rolling down the slope. As it rolls, it picks up snow rapidly on the underside, becoming asymmetrical. The weight of the "upper" side of the ball is enough to keep the object moving. It sort of rolls and sort of deforms (somewhat like a wave breaking) until the elevated part of the object touches down, completing the donut.

Of these two scenarios, number 2 seems improbable to me, especially considering the low angle of the slope shown in the picture above. It doesn't seem like the forces work out right in this scenario. Number 1 seems like the most probable explanation. I wonder what the truth is...   ???

Once I got knocked off my skis by a snow honey bun, sorry no pics

I found this one on the Pipeline trail near Mission Ridge last January while snowshoeing.  I'd never seen one before either!  ???

Found the hole ....  There were no trees within 10 feet of this hole in the snow.  Very strange and I thought I'd never have a chance to use this photo!