Sleeping Bags

Big Agnes Lost Ranger Review

The Big Agnes Lost Ranger is a 15 degree down sleeping bag with winter temperature ratings that packs a lot of warmth for its weight. The 650 fill duck down keeps weight down while keeping affordability in mind.

Picking a winter sleeping bag can be a confusing operation.

Coming in under 3lb’s, the Big Agnes Lost Ranger checks a lot of boxes for us looking for a cheap, mid-weight, winter sleeping that can easily fit into your pack.

Big Agnes Lost Ranger 15 Sleeping Bag


  • Simply Roomy – big? – side sleeper? no problem.
  • Packable / Good compression
  • Very light for its warmth
  • Quality construction
  • Good zipper
  • Affordable
  • Works well with a NeoAir
  • Closer to a 10 degree bag warmth wise
  • Built-in external sleeve for a sleeping pad


  • Requires sleeping pad to be effective (usually not an issue)
  • Bellowing effect when you move your legs can sometimes pull in cold air
  • Some cold Cold spots
  • Collar sometimes gets in the way
  • Not the best for those who roll around in their sleep

Feature Summary

  • 650 fill-power DownTek insulation absorbs 30{6ae4d48c96d66710345507933be5e8d0ff05184660bc2c1189ea28c61d96508c} less water and dries 60{6ae4d48c96d66710345507933be5e8d0ff05184660bc2c1189ea28c61d96508c} faster than untreated down, and retains significantly more loft than untreated down after exposure to moisture
  • An external built in sleeve design keeps your sleeping pad layer next to your body for more efficient heat distribution and reducing drafts.
  • Ripstop shell fabric is soft and does have a DWR finish to reduce issues from splash
  • Low-profile cordlock lets you un-cinch the hood with just one hand
  • Tapered, vaulted footbox creates wiggle room for your feet without creating large cold air pockets
  • Stretch fabric panel beneath hood creates a designated pillow pocket
  • 70″ zipper (almost full length)
  • Left and right pair of sleeping bag zippers can be joined
  • Includes a mesh storage sack and nylon stuff sack

External Sleeping Pad Sleeve

The sleeping bag includes an external sleeping pad sleeve to keep everything in place while you sleep.


The Lost Ranger uses 16oz of 650fp treated goose down. Rated to 15f by the amount down can actually be taken down to 10f safely with a proper sleeping pad and some thermals.


At 2 lbs, 12 oz, this sleeping bag isn’t the lightest winter sleeping bag on the market but compared to other 15f or probably better compared to 10f bags it actually holds its own.

Comfort & Sizing

Big Agnes seems to follow a pattern of catering to the bulkier guys and the Lost Ranger is no different. Roomy in a word. Even the regular fits up to 70 inches of shoulder room. That’s roomy even for a stocky 6foot gut like me.

The almost rectangular shape of this sleeping bag also adds much needed comfort levels for those that can’t lie still at night or sleep on their side.

While the sleeping pad sleeve makes up for the non mummy shape, its a bit of a pain for those who roll around a lot.

Because of the large opening, entry and exit are very easy in the dark of night.

Big Agnes Lost Ranger Packed Size

The 650 fill allows the Lost Ranger to pack down relatively small, actually surprisingly small for a 15f sleeping bag. I have a 900fp 20f sleeping bag that only packs down a little bit smaller.


Big Agnes has solid QA & Testing practices to ensure their products hold up to the harsh environments you plan to put this bag through.

Big Agnes Lost Ranger vs Encampment

The Big Agnes Encampment is the Synthetic insulated version of the Lost Ranger. The sleeping bag design (including sleeping pad sleeve) is the same. The only real difference is in the insulation type. With Down you have better compression and less weight for an easier carry. For most climates and conditions it can be advised to go with the Down version as keeping your down sleeping bag dry is actually pretty easy these days. For extremely damp or snowy climates like parts of Canada, Australia, and New Zealand it can be a smart choice to go with a synthetic option like the Encampment.

Less of a deciding factor but worth a mention is that down tends to breath easier and synthetics tend to feel clammy.

The Verdict

Perhaps a gimmick, the sleeping pad sleeve makes a big difference in warmth for those cold sleepers out there needing a little extra protection. Personally I wouldn’t hold sleeping bag as my go-to – I’m a serial side, stomach, curled up and roll around sleeper that wouldn’t find this comfortable for nights on end.

While holding that opinion, the warmth, the packability, and the roominess makes this a unique unmatched sleeping experience for the bigger body types like myself.

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Frequently Asked Questions

Will regular be too short for someone who’s 6 foot?

Regular will fit you perfectly. Any taller and I would suggest getting the long.

What pad do I need for my big agnes lost ranger long sleeping bag? Or can I just use a standard rectangular foam pad I have? Does the thickness of the pad matter?

The regular fits a pad that measures 20x72x4.25″, the long fits a pad up to 20x78x4.25″, while the long wide fits a pad up to 25x78x4.25″. Most sleeping pads (including inflatable) will fit this bag.

Is it possible to zip two of these together?

Two Big Agnes Lost Ranger sleeping bags can be zipped together provided you have both a left and a right zip version. The Big Agnes Roxy Ann (womens version of this bag) is also compatible.


Best UseBackpacking
Temperature Rating (F)15 degrees Fahrenheit
Temperature Rating (C)-9 degrees Celsius
Long Left
3 pounds
Long Left Wide
3 lbs. 7 oz. pounds
Regular Left
2 lbs. 12 oz.
ShellRipstop polyester
Zipper LocationLeft
Insulation TypeDown
Water-Resistant DownYes
Fill650-fill DownTek down
Fill Weight
Long Left
19.5 ounces
Long Left Wide
24 ounces
Regular Left
16 ounces
LiningPolyester taffeta
Sleeping Bag ShapeSemirectangular
Fits Up To (in.)
Long Left
78 inches
Long Left Wide
78 inches
Regular Left
70 inches
Shoulder Girth (in.)
Long Left
73 inches
Long Left Wide
80.5 inches
Regular Left
70 inches
Hip Girth (in.)
Long Left
68 inches
Long Left Wide
75 inches
Regular Left
65 inches
Stuff Sack Size
Long Left
8 x 17.5 inches
Long Left Wide
9 x 20 inches
Regular Left
8 x 17.5 inches
Stuff Sack Volume
Long Left
14.5 liters
Long Left Wide
21 liters
Regular Left
14.5 liters
Compressed Volume
Long Left
5.05 liters
Long Left Wide
6.52 liters
Regular Left
4.35 liters