Big Agnes Lost Dog 30 Sustainable Sleeping Bag Review

The Big Agnes Lost Dog 30 Sustainable Sleeping Bag is known for its spacious design and recycled materials. Designed to fit campers up 6’6” in height, this sleeping bag features a lightweight synthetic fill and insulation made from 100% recycled post-consumer polyester.

The Lost Dog 30 is part of Big Agnes’ Sleep System collection, all of which are designed to fit perfectly with Big Agnes pads/mats. Thus, the bags won’t move around or shift while you’re sleeping. Not only are these bags designed with comfort in mind, they also come with lifetime warranties that offer peace of mind for the life of the bag.

About Big Agnes

Big Agnes is an award-winning maker of outdoor gear, known for products that push the envelope when it comes to sustainability. During the past 20 years, Big Agnes has made achievements in creating highly technical products made with recycled materials.

Big Agnes Lost Dog Non Toxic Sleeping Bag Made from Recycled Materials

Design Features

Lightweight synthetic fill

  • The Big Agnes Lost Dog 30 Sleeping Bag is filled with FireLine ECO Synthetic Insulation made from 100% post-consumer recycled polyester.
  • The synthetic insulation helps reduce air pockets between the body and fabric, and creates  maximum heat retention to keep you warm
  • The sleeping bag insulation is lightweight, with a total weight of just 3lb 4oz. This gives you warmth without a lot of excess bulk.

Roomy, rectangle shape

  • The Lost Dog 30 Sleeping Bag has a spacious 72” of shoulder room and 52 inches in the footbox, allowing big and tall hikers to move around with ease.
  • It’s roomy, rectangular shape makes it possible to fully extend your arms while sleeping, as well as stay comfortable on your side or stomach.
  • The shape allows campers to shift their position without feeling cinched or constrained—perfect for side sleepers! 

Flex Pad Sleeve for integration with sleeping pad

  • The Lost Dog 30 has Flex Pad Sleeve that works with any compatible Big Agnes sleeping pad.
  • The Flex Pad Sleeve keeps you from slipping off your pad throughout the night.
  • This sleeping bag is designed to attach to most 20″-25″ wide x 78” long pads.

Draft collar, draft tube, and pillow barn

  • The Lost Dog also includes a draft collar, draft tube, and pillow barn to lock in warmth and cushiony comfort.
  • The fitted jacket style hood with draft collar seals out cold air while providing ventilation. This keeps the interior of the bag warm air without trapping moisture and heat.
  • draft tube runs along the zipper of the sleeping bag to keep cold air from seeping through.
  • Finally, there’s also a pillow barn on one side of the sleeper so your pillow will remain securely attached during sleep.

Lifetime warranty

  • Customers get peace of mind knowing that their investment in this quality product is protected with a lifetime warranty.

Technical Features

Temperature rating

  • The Lost Dog 30 Sleeping Bag has a temperature rating of 30°F, which is slightly above freezing.

Weight and dimensions

  • The Lost Dog 30 weighs 3 pounds and 4 ounces.
  • It measures 78 inches long and 25 inches wide when fully unrolled. It’s large enough for an adult sleeper up to 6.6 feet, with room to move arms and legs.
  • The Lost Dog shrinks down to 7 x 9.5 inches – making it easy to take anywhere you need !


Use of 100% recycled insulation

  • The Lost Dog 30 Sleeping Bag is made with recycled insulation and polyester.
  • The sustainable materials offer the same level of performance as traditional insulations, without compromising on quality or comfort.
  • This type of insulation helps reduce waste by using existing materials and reducing your environmental impact.

Comparison to Other Lightweight Sleeping Bags

Compare the Lost Dog 30 to similar Big Agnes models such as the Lost Dog 15 and 0, highlighting any key differences you find. Encourage readers to get more details about these features so they can make an informed decision when buying a new sleeping bag.

Similarities with the Lost Dog 15 and Lost Dog 0

  • The Lost Dog 30 Sleeping Bag is part of a series of sleeping bags that includes the Lost Dog 15 and the Lost Dog 0.
  • This family of sleeping bags are all made with lightweight synthetic fill, FireLine ECO insulation, and a roomy rectangle shape for increased comfort.
  • The recommended height and width for optimal fit on all three products is the same. However, each product has distinct features in terms of warmth ratings and materials used to achieve it.
  • The Lost Dog 30 offers a warmth rating of 30°F (slightly above freezing) while the Lost Dog 15 boasts a 25°F rating and the impressive 0°F rating on the Big Agnes rotationally molded pad sleeve version.
  • All three models also feature both down insulation fill material as well as polyester so they’re really warm without adding too much weight.

Differences with the Lost Dog 15 and Lost Dog 0

  • The Big Agnes Lost Dog 15 and Lost Dog 0 have lower temperature ratings ranging from 15°F-0°F depending on the model.
  • They also feature more compact mummy shapes rather than rectangle opens bottomless designs of the Big Agnes Lost Dog 30.

Final Thoughts

  • The Big Agnes Lost Dog 30 Sleeping Bag is a lightweight and packable sleeping bag with plenty of comfort features. With a weight of just 3lb 4oz, it’s easy to take on any camping trip.
  • It’s insulated with FireLine ECO Synthetic Insulation, made from 100% post-consumer recycled polyester for increased sustainability.
  • The sleeping bag fits campers up to 6’6″ tall and has roomy dimensions designed for comfort; it measures 79″L x 25″W and accommodates mats measuring 21″-25 ” wide x 78” long.
  • The sleeping bag is designed to keep cool air out, while the wedge insulation at the footbox keeps heat concentrated around your toes.
  • The robust craftsmanship comes with a limited lifetime warranty for extra peace of mind.


The Big Agnes Lost Dog 30 Sleeping Bag is an ideal product for anyone looking for reliable warmth and comfort while out camping in the 3-season months. It has all the features campers need – lightweight synthetic insulation, a cozy vaulted footboxtwo-way locking zippers, and no-draft collars to keep drafts out – at an incredibly affordable price point of $184.94 USD.

Plus, it comes with a lifetime warranty and uses 100% post-consumer recycled polyester so you can protect your wallet all while helping reduce environmental waste. With its FireLine ECO insulation and roomy fit perfect for adults up to 6’6″, this sleeping bag will provide dependable performance on your next hiking or backpacking adventure.

Disclosure: This website contains affiliate links. When you click on these links and make a purchase, we may earn a commission at no additional cost to you. We only recommend products or services that we genuinely believe in and have either used ourselves or extensively researched.

Fair Trade Finder