There used to be a group of women in our ward that would take a short "mom's day off" trip for a long 3-4 day weekend every year - leaving their husbands home to care for the kids. One year they went up to West Yellowstone in January and did some snowmobiling in the park. One of them accidentally went off an embankment and ended up dying. Husband and kids made it up to the hospital in Idaho in time to say goodbye before they unplugged her.

Whenever I think of Yellowstone in the winter - that's all I can think of. Sorry.