[LakeCleElum]

Great idea - You have to see the parks at least once in your lifetime in the winter.....Hopefully you understand you can't drive in Yellowstone in the winter and have to take a "tour". This could be in a large van type vehicle with "tracks" or go on a snowmobile you would rent?

Yes, clothing is available to rent at shops that rent ski's and snowmobiles.....Due to cold temps, I'd suggest late Feb or even March...I've done Yellowstone 5 times on my own snowmobile. Coming from the West, I've always stayed in West Yellowstone and only been to Jackson Hole in the summer.

Also, understand it's quite a drive in winter driving conditions from a major airport.....Flying straight into Jackson would probably be a good plan.....Two roads thru the "Tetons", take the one to the west, you are much closer to the scenery.......To get into Yellowstone from the south, Flagg Ranch seems to run most of the tours.........G'luck..