Thanks for all of your input. Some good ideas I will be incorporating in my pack. Some other observations: From other snowmobile forums, it seems the few who accidentally spent the night, they all just fed the fire all night and stood around the big depression in the snow and waited for daylight. I kind of assumed that I would do that as well. I wonder if the snow cave, makeshift lean to around a pine tree type of shelter wouldn't hinder the fire, or be worth the effort, but something to pass the night has it's benefit as well. I would have to guess there would be from 2 to 6 of us hanging round, waiting for the snow to freeze back solid enough to ride out, or morning and a chance to get gas/ parts to get out on our own. If it were more of a longer term survival situation, hurt, lost or ? then I would probably invest in the shelter, and of course it would depend on temperature and weather conditions... Is there a compelling reason to construct a shelter, by the way, I'll be dressed rather warmly, layers, etc...extra longjohns, socks, wool sweater, hats and gloves..my kits contains the stuff.. saw, knifes, trash bags, para cord, fire starters, bailing wire, zip ties, whistle, shovel, probe, avalanche beacon, cell phone (won't work but) walkie talkie, gps, and more..., never leave home with out a travel plan on a trusted friend/wife. So is sitting out the night around a bigger fire inherantly more risky?