Make cold nights warm.

Whoever decided to camp in the middle of winter probably stays nice and toasty in Mountainsmith's Berthoud Sleeping Bag. This bag is undoubtedly Mountainsmith's warmest option in the Berthoud collection, and its synthetic insulation ensures warmth when snow seeps through the tent. Mountainsmith made the bag's shell out of snow-shedding materials, while the taffeta lining gives a soft feel. The Berthoud also features a form-fitting hood, multiple adjustments, a draft collar, and a tube that runs down the entire zipper to prevent cold drafts from waking you up in the middle of a ridiculously frigid night.

  • Mountainsmith's warmest sleeping bag in the Berthoud collection
  • -20F temperature rating suitable for winter camping
  • Synthetic insulation stays warm when wet
  • Water-resistant shell sheds snowflakes and icy water
  • Adjustable, form-fitting hood assures a secure fit
  • Draft tube and draft collar keep cold winds at bay
  • Reviews
  • Q & A


Good enough for car camping

  • Familiarity: I've put it through the wringer

I purchased this bag based on the temperature rating alone and wish I had done more research. It was supposed to replace my old Guide Series 0 degree bag and I was hoping to get something which could stand up to winter camping in middle-west and northern Michigan's bitter cold. I don't think this was warmer than my bag rated for 0 degrees (Fahrenheit). This last trip we had temperatures as low as -10F and this bag wasn't warm enough. For the remainder of the trip, I put another sleeping bag inside it and another sleeping bag unzipped over top to stay warm. (That did the trick.)
It doesn't pack down as well as my other car camping 0 degree bag, either. This bag is dense and barely fits into its stuff sack, which isn't small. (I'm posting from work otherwise I'd share the dimensions.) With as dense and heavy as it is, it feels robust and I expected something much warmer.
As another complaint, the hood portion is very difficult to tighten down. I ended up sleeping with my trapper hat on because I couldn't get the mummy top tight enough and there was a draft all night. I think it's in part due to the tightening cord itself, but also because the material is so dense it didn't want to tighten down past a certain point. Eventually, it was too difficult to do with mittens on and my hands were getting too cold without mittens so I gave up and tossed on the hat and a scarf. That was good enough for that night. I've only slept in it in harsher conditions three times so I am hoping perhaps additional use will help? We'll see.
As to the other comment which says it has been stored in the stuff sack--mine arrived in the storage sack and did not look like it had been too compressed so maybe that was a fluke or Backcountry fixed the issue.
Overall, this bag would probably be great for car camping in temperatures not terribly far below freezing, perhaps in the 20s F. I do not recommend it for the extreme cold. It certainly isn't recommended for winter backpacking. For the price, it's a great beginner bag for people looking to get into car camping in winter conditions, so long as the winter conditions are not too harsh/bitterly cold.

bag was stored for a year in stuff sack

  • Familiarity: I've put it through the wringer decided this bag was best stored for a year in the stuff sack so the -20 bag has no loft after a couple days. Not mountainsmiths fault, its all on