Do I really need a bivy for snow camping?

Quick question- is there any reason why synthetic clothing used inside a down bag would NOT have the same effect as the synthetic liner bag?
I have been using my DAS parks inside a WM Antelope for winter… but rarely for more than a few days. I always assumed a synthetic overbag, or down clothing inside a synthetic bag, would be a better bet for longer trips.

Also, ID makes the Primaliner as another liner option.

I just found out that my snowcaving has been cancelled because the council can't get the insurance to have such a big event.
TOTALLY BUMMED!

Thanks for all the feedback, hopefully next year.

I will be able to apply some of what you said because I am going to the Klondike in Jan.

-Evan

Evan, sorry to hear about the council cancel.
Why don't you organize a smaller group and get one of the "experts" to go along. The council should give you the tour permit for it. I get a tour permit every year for iglooing from our council. Don't back out now you are almost there!

Alright, I will try to organize it with my scoutmaster. Perhaps theres a chance we can still go.

I have had great luck with a synthetic overbag.
For years I used a Camp7 polarguard overbag. By itself
it was good to about 45 F.

I have also had good luck with pulling my insulating top
clothing on over my feet either inside or outside my sleeping bag to ward off cold feet.

My Goretex parka outside the bag, over my feet makes a good
half bivy. If you roll off your pad is give some protection.
If you are under the stars, it provides some radiant heat
loss protection.

A full or partial bivy is useful in dripping snow caves as is found
in the Northwest. IE when you didn't bring a shelter,
planned on snowcaves and the weather warms or rains.
I have had caves drop over 2 feet in height in one night.
Drip, Drip Drip. "Should we get out of here while we still can?"

Better ventilation of the cave helps, but it is hard
to get up to fix it in the middle of the night after
you discover the problem. (This is also when I learned
the value of a pee bottle.)

A bivy keeps you on your pad and keeps snow from
getting caught between your pad and bag. Especially
if you have one of those ridged thingys designed to
catch every flake and melt through to your backside.

For cold and potentially wet multi- day trips I liked the
belt and suspender approach:

VBL
clothes
summer down bag
sythetic bag
full length foam pad
bivy
hot water bottle
tarp or snow cave

Sheer Luxery

Yo Evan! you don't get off that easy.. I mean, you DO have snowbanks there in Northern ID? You can go all out in your backyard, eh? Lots of people in Tahoe have little snow caves in their yard. My igloo lasted about a month, despite little kids overrunning it, literally.

For a snow cave, remember to take off all your warm clothes and put on the goretex and WP gloves. Shoveling headfirst in a little hole is damp and warming, but you also are having a preview of the warmth of the cave.

If you have enough sticky or slabby snow, it only takes a couple tries at an igloo to start getting some good results. A snowsaw is great, but you can cut blocks with a pruning saw or handsaw. If your snow is not consolidated, you can stomp it down with snowshoes and wait for a while or even the next day. Primo blocks.

Option 3 Quinzee, the low-snow option. Make a voluminous gear pile rolled in plastic sheet and pile the snow on, pack on a good thickness of snow. Wait to set, and remove gear. Expand hole as needed or if possible.

That book though, it explains everything concisely, and at a glance. So fun.

One of the things we have to remind the kids when they
are learning to build snow caves.

You can't hear the plows coming.

Paul, the place many troops go to is Lookout pass. There are snow banks there.

Plus it would be some crusty and tough stuff! If you encountered that much difficulty in the backcountry, it's a great idea to try somewhere else for better conditions. Other areas to avoid around the house are under the roof avalanche zone, or over the compost heap or septic.

Way to motivate Evan! Snowbanks are the quickest, and nice because it's easier to have your entrance lower than the sleeping area, to retain heat. Probe first like in Mike's photo. A nice short-handled shovel is key, like a backcountry avalanche shovel. I despise the SnowClaw, but it can be used for clearing snow.

Tip: If your entrance is too flat to drain the excavated snow, you or a helper can use a piece of plastic on the floor to help drag it out. Tie a knot in the end if you lose too much when they pull it. They haul it out, throw the other one in, and go dump #1 while you fill #2. Less waiting and getting cold for the folks outside, and quicker for you.
This would be for a big multi-person cave, not just a survival hole.
Edit: it can put holes in the plastic, depending.

Thats a good idea, Paul.

It does beat on the plastic, so consider that if using your goundsheet for the purpose. It could potentially get a hole, especially if you start down at ground level or there are sticks or pine needles in the snow.

Evan, you don't need to use the road snow banks. there should be enough areas off of Highway falls on either side of the freeway. Just get off the road and look for a hillside.

The negatives:

Do not suffocate yourself. Ski-pole out some good size vents and do a 70% job of blocking the the door with a pack.

Do not warm up your cave much above freezing and start water dripping on you, or even potentially weaken the roof.