Cwm -40° Sleeping Bag – Marmot

(10 customer reviews)


Welcome to the outer limits, astronauts. High-quality 800+ fill goose down and MemBrain® waterproof, breathable fabric form the core of this portable environment—designed to deliver restful sleep, down to –40°F, in the harshest alpine environments. Over-engineered with sturdy reinforced linings and countless baffles for a lifetime of dependable comfort and protection.





10 reviews for Cwm -40° Sleeping Bag – Marmot

  1. Sophia11

    Although this bag adds some extra weight to my pack, it allows me to rest assured that I will be warm and cozy after a long day of playing hard outside. I’m now using this bag for my second.

  2. Jill1987

    I bought this sleeping bag after a North Face -20 Inferno bag proved not warm enough on some trips to Alaska or western Yellowstone in the winter. My biggest complaint with my old bag, other.

  3. RustyCrampon

    Just got back from a month climbing Pumori in the himalayas. This bag was the only thing that kept me sane and warm when it got to -15 degrees every night.

  4. Riah

    I bought this bag for using in the winter in Utah during my wilderness therapy stints. It is super warm, waterproof (to a point.

  5. Rocky29oct

    I bought this bag due to great reviews and also mainly due to stuff size of 9.5 x 19. However, i rec… Show Full Review This action will open a modal dialog.

  6. flybird

    I heard from co-guides about this magical sleeping bag and decided to commit to it for this winter as it gets down to -20 with windchill in our field area. It’s keeping me way toasty already.

  7. Grizzled

    Let me start off by saying that I have owned this sleeping bag for at least 5 years and spent at least 100 nights in it. It has kept me toasty warm to below -40 through all of it and hss exceeded.

  8. AdWolf

    Loving this bag! It’s kept me warm out in the woods during -4 degree weather. There is a liner feature that sits above your shoulders to keep warmth in and cold air out.

  9. Anonymous

    I used this sleeping bag on Denali this year during the early climbing season. With 25 days on the … Show Full Review This action will open a modal dialog.

  10. JimGriffs

    I used this on Everest, and found that my 25yo Western Mountaineering bag was warmer than the Cwm. The small-gauge zipper often jammed, and rarely slide to the top of the track.

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