Sunday 21 August 2016

Thoughts on Bivouacking

In the Grand Canyon

My favourite way to spend a night in the wilds is under the stars – no tent, no tarp, and no bivi bag. I’ve been thinking about this following some recent discussions of bivouacking on social media in which the use of a bivi bag was assumed. I wonder why. In any circumstances where a bivouac will be pleasant a bivi bag shouldn’t be needed. And if bivvying won’t be pleasant I’m not going to do it unless there’s no other choice. If rain, snow, strong winds or biting insects are likely then I’ll use a shelter I can actually live in not a bag in which I can do nothing but sleep. That means I rarely bivi in Britain despite my love of it. I am planning on some forest bivis on calm nights this autumn once the midges are gone however. I’ll take a tarp as well though, just in case of rain.

In the Superstition Mountains on the Arizona Trail
Most of the bivouacking I’ve done has been in dry areas where rain was very unlikely. I first learnt how much I enjoyed this on the Pacific Crest Trail when I realised early on that I didn’t need my tent most nights. Only when the mosquitoes came out and in the rain and snow in the North Cascades did I use the tent often. I slept out many times on the Continental Divide Trail too and almost every night on the Arizona Trail and on a month-long walk in the High Sierra. 

In the High Sierra
On these trips I would lay down a groundsheet – over the years these have gone from silver Sportsman’s Blankets to much lighter weight silnylon ones – and then my mat and sleeping bag. My kitchen would be set up next to the groundsheet so I could cook and eat while in or on my sleeping bag. When using a pack with a frame I’d use my trekking poles to prop it up for use as a back rest. (This doesn’t work with frameless packs – at least not for me). With everything I might need to hand – notebook, reading matter, maps, headlamp, clothing – I could then spend a restful evening with the world I’d come to be part of all around me. I’d fall asleep staring up at the stars and the silhouettes of trees or mountains rather than a sheet of nylon.

Larry Lake at a bivouac in the Yosemite backcountry on the Pacific Crest Trail
The key to comfortable bivouacking like this is dryness. Cold doesn’t matter – I’ve had many pleasant bivouacs in sub- zero temperatures. Wind can be a problem but as long as it’s not too strong a tarp or groundsheet can be used as a windbreak.  This blocks off some of the view but still gives more freedom and contact with nature than a shelter with a roof.

Using my groundsheet as a windbreak at a chilly bivouac on the Arizona Trail

On none of these bivouacs did I need a bivi bag. Sometimes my sleeping bag has been dew or frost covered in the morning but this has always quickly dissipated in the sunshine. And on the few occasions when I have packed a slightly damp bag airing it during the day or at the next camp has dried it. 

When I’ve slept in bivi bags to try them out I’ve usually found a little dampness inside (sometimes more than a little). The only times I’ve chosen to use bivi bags have been in dripping bothies and tents (either from rain getting in or copious condensation – which can occur in badly ventilated concrete shelters as well as tents). A few times I’ve used a bivi bag for extra warmth when sleeping out in very cold temperatures in the winter in Norway and Sweden. Each time I’ve woken to a thick layer of frozen condensation inside the bivi bag. I’d have been better off with a warmer sleeping bag or clothing.

Just once I’ve slept in a bivi bag in heavy rain. This was the first night of a walk in the Pyrenees. Tired from the long train journey from the UK my companion and I had decided not to bother with our tents but just collapse into our sleeping bags on the ground. That night for the only time on the two-week trip it poured down. Woken by the first drops we quickly wriggled into our bivi bags, turning them over so the zipped opening were underneath to prevent leakage. We stayed dry but I was very relieved when dawn came with a clearing sky and I could escape from the restrictions of the bivi bag. I wouldn’t do that again by choice.

Almost a bivouac - a tarp pitched to ward off wind and light rain on the Arizona Trail

Rather than gear I expect to use I view a bivi bag as an emergency item, to be used if I get stuck out on a day walk or if my shelter fails in some way. Used like this a bivi bag lasts a very long time!


  1. Interesting article Chris, thanks for sharing your thoughts. From your many travels and (I assume) having tried different groundsheets, which have you found to be the best?

  2. They've all been ok. Silnylon is very light so that's what I use now. It is slippery though, especially when new. Some stripes of Silnet seam sealer helps with this.

  3. Good article, thanks. My thoughts on Bivouacking (bag or not) are mixed from quite a number of attempts at it over the yesrs in remoter areas and semi urban. Various ideas circle as to why I think it works well for some and less for others but the short of it is that my sleep always seems to be very very shallow compared to tent sleeping, with things like a hangover from evolutionary vigilance about sleeping out exposed possibly playing a part depending on where I am, which have been confirmed in some respects by myself and others who have inexplicably woken up to look over and see someone in the dark staring at them in various settings, such as on beaches or semi urban. Issues of personal safety and concern about gear theft come into play there, and it seems a sixth sense is at work based on these findings. I appreciate this is much much less of an issue outside of populated areas, but even in much more remote areas my sleep seems to be shallow with multiple wakings. It is amazing how much of a difference the tent makes to this. Unless I can be 100% sure nobody is going to be around (and it amazing how people can appear in the middle of nowhere), the vigilance part of my mind never fully switches off as it does in a tent.