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Get lost. Stay warm. Stay protected.

The Big Agnes Lost Ranger 15 Sleeping Bag blends backpacker-friendly weight with bad weather camping protection. DownTek treats the lofty down insulation with water-resistant protection to retain its loft and warmth in rainy weather and moisture-riddled environments. Insotect Flow Construction optimizes insulation by strategically placing vertical chambers with Flow Gates to minimize shifting and to ensure warmth where you need it most.

Big Agnes also equipped the Lost Ranger with a water-resistant shell and a downproof lining for extra protection and comfort. The lining has loops to attach separate liners, and draft tubes cover the hood, collar, and full-length zipper to keep brisk breezes at bay. For a roomy rectangular-shaped bag, the Lost Ranger is surprisingly light and compressible to take backpacking. Since Big Agnes doesn't insulate the bottom of bags, be sure to pair this sleeping bag with a 20in sleeping pad.

  • 15F temperature rating
  • DownTek water-repellent down insulation
  • Insotect Flow Construction
  • Rectangular shape
  • Water-resistant shell
  • Downproof lining
  • Draft tube around hood and collar
  • Full-length zipper
  • Pad sleeve and pillow pocket
  • Internal fabric loops
  • To reduce weight, Big Agnes sleeping bags have no insulation at bottom

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Here's what others have to say...


Nearly perfect backpacking sleeping bag

  • Familiarity:I've used it several times

I got the Lost Ranger 15 because I wanted something WARM that didn't weigh a ton or cost an arm and a leg. The sale price offered by was unbeatable, so I took the plunge. Big Agnes has hit on a very smart concept with their bags. Eliminating the insulation on the under side and relying on a good sleeping pad for that area where you just smash the down flat anyway saves a bunch of weight AND bulk, which makes this bag easy to stuff and highly compressible--saving lots of room in the backpack. This design has also allowed them to fill the upper part of the bag generously with the down where you really need the insulation in the first place. It also allows them to cut the bag much more generously than what you typically feel in a traditional "cold weather" mummy type bag. I LOVE the extra roominess in this bag. It's still a mummy shape, but it's not at all constricting like most others I've tried, and allows me to easily roll over and change positions, and I never feel like I'm wrapping the mummy webbing more tightly around me like I do in other bags. It's glorious NOT feeling like I have to sleep in the funeral position on my back only. It's hard enough to get a good night's sleep in the backcountry without fighting your bag for it. There's no fight with the Lost Ranger--it really does feel different and roomier, yet not loose and warmth challenged. The added bonus of the non-insulated underside is the built in sleeping pad sleeve that works like a charm with any 20" wide pad. I teamed my Lost Ranger with the Nemo brand Cosmo Air 20 pad (72" long) and it mates perfectly inside the sleeve. The built in openings at the corners of the sleeve are perfect for the inflation and deflation valves as well. With my pad securely held inside the sleeve, I NEVER have to worry about rolling off my pad, and when I move around and change positions as indicated above, the pad stays right where it's supposed to--directly underneath me. I am VERY, very happy with this purchase and the way it all works together for comfort as well as light weight. I haven't had the bag out in extremely cold weather yet--nothing below 30 degrees, but I'm confident it will perform as advertised. It just has that feel to it and fluffs up very nicely. I highly recommend this bag to anyone looking for a good deal on a colder weather bag with premium materials and design. Big Agnes knocked it out of the park with this one. And thanks Backcountry .com for beating everyone's price!! And for getting it to me in only two days for no extra charge. Great purchase experience.


So far so good...

  • Gender:Male
  • Familiarity:I've used it once or twice and have initial impressions

I purchased the lost ranger along with a sea to summit silk liner, the thermarest base camp sleeping pad, and the thermarest luxury lite mesh cot. I tried the combination in the house overnight and it was very nice. I took it car camping in rainy cool weather.. It got down a little below freezing and all was well. With a pillow in the sleeve under the bag it works perfectly... This combination of bag pad and cot is amazing... I will never go back on the ground. This is the best sleeping bag I have ever owned.

I plan on going camping again in a couple of weeks. The evening should bring lows in the twenties and possibly teens. I will have a better idea then of how well it holds in the heat. I am a hot sleeper desire to spend time outdoors has now been tapped again thanks to the comfort level I have achieved with this new combination... Whew!


Good bag

  • Familiarity:I've used it several times

Buy it and you will be happy..... wish it weighed 1/2 as much and cost 1/2 as much.... but if you are like me and a little harder on UL gear... then you know the value of quality.... this is a good bag and I sleep pretty good in it. 5'10" - 227# ...and am wide in the shoulders/hips....
Extra thoughts.... I will say this is too warm a bag for me in the summer with an insulated pad..... go without an insulated pad in 40F+ or pack a Woobie instead.


Embrace It....

    Ok, so let's get to it...I have always HATED the traditional mummy bag and (insert favorite pad here) combo. Endless nights pent sliding off your pad, kicking your feet around for room that's just not there, you know, all the stuff that us "mobile" sleepers hate. On the flip side, have never wanted to deal with the weight of rectangular bags or other pseudo car camping setups. Problem now solved. Enough room to flail around, but not so much that it feels chilly, integrated pad sleeve means that you may indeed slide, but not off the pad. And for some reason, when you integrate the pad to bag like this it just feels cozier. Weight is decent, especially when paired to the new and very awesome Therm-a-rest Evolite pad. Look, to the many that I know feel the same way...stop fighting it. A good nights sleep in the BC is worth a little extra weight, and to your purist friends who may deride you? Let them test lay in it and they may never give it back....

    What pad sizes work with this sleeping bag?

    Pad sizes that work with each sleeping bag size:

    Regular (Sleeping Bag): 20"x72" or 51cm x 183cm

    Long (Sleeping Bag): 20"x78" or 51cm x 198cm

    Anytime you have a Big Agnes question, shoot me an email and I'll make sure to work with you 1-on-1!

    Jared D.

    Expert Gearhead


    Best Answer

    Jared can a left and right zip lost ranger be zipped together?