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Hyperlite Mountain Gear 3400 Southwest Backpack Review

Hyperlite Mountain Gear 3400 Southwest Backpack Review

Hyperlite Mountain Gear 3400 Southwest Backpack


Superlight, Super Durable!

The Hyperlite Mountain Gear 3400 Southwest Backpack is a bomber multi-day backpack geared for tough adventures that will rip most other ultralight-style pack to shreds. If you're rough on backpacks, but still want one that only weighs two pounds, the 3400 Southwest pack probably has your name on it.

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The Hyperlite Mountain Gear 3400 (55L) Southwest Backpack is a durable Dyneema DCF (formerly called cuben fiber) backpack that’s good for thru-hiking and multi-day backpacking trips in rugged terrain. The 3400 Southwest is basically the same pack as the smaller volume Hyperlite Mountain Gear 2400 (40L) Southwest Backpack (SectionHiker Gear of the Year) but with a longer extension collar, so you can stuff more gear inside. This is handy if you need to carry a few more days of food, extra clothing, or more sleep insulation on longer trips or in colder weather.

Specs at a Glance

  • Weight: 32.4 ounces (size large)
  • Gender: Unisex
  • Closure: Roll top
  • Frame: Internal (2 Aluminum Stays)
  • Pockets: 3 external, plus main
  • Max Load Capacity: 40 pounds
  • Materials: 50D and 150D Cuben /Polyester Hybrid and Dyneema Hardline pockets
  • Volume: 55L w/ 9.8L of external storage

Backpack Storage and Organization

The Hyperlite Mountain Gear 3400 Southwest Backpack is laid out in a traditional ultralight style with a large main compartment, side water bottle pockets, and a large rear pocket.

The HMG 3400 Southwest has a dry bag style roll top and solid external pockets
The HMG 3400 Southwest has a dry bag style roll top and solid external pockets

The main compartment has a dry bag style closure system which provides excellent top compression for stabilizing your load. The fabric of the cuben fiber pack body is also waterproof and the interior seams of the pack are seam taped, making the pack highly resistant to rain.

The main compartment has a mesh hydration pocket and hydration loop if you want to carry a water reservoir/hose inside the main compartment. Since I prefer using water bottles, I use this pocket, which lies in between the two frame stays, to store maps instead.

Interior of main compartment showing mesh hydration pocket and taped seams
Interior of main compartment showing mesh hydration pocket, hang loop, and taped seams.

There are five external pockets on the 3400 Southwest Pack, two side water bottle pockets, a larger rear pocket, and two hip belt pockets. All of the pockets are made of solid 210 denier Dyneema reinforced nylon (Dyneema Hardline), enabling the pack to be used roughly or in off-trail conditions that would quickly shred mesh pockets.

The side water bottle pockets are large enough to comfortably fit 1 liter water bottles together in addition to tall skinny items like trekking or tent poles, and have drain holes at their base. The bottoms of the pockets are reinforced at the base with a 150 denier cuben fiber/polyester to prevent punctures or tearing – an important durability feature. Water bottles stored in the side pockets are also reachable and replaceable while wearing the pack, a must-have.

The rear pocket is large enough to store my hammock tarp, cook pot, wood stove, stake bag, hydration reservoir and sawyer filer, as well as extra rain layers - basically the stuff I don't want in the main compartment because it's wet or smelly.
The rear pocket is large enough to store my hammock tarp w/snakeskins, cook pot, wood stove, stake bag, hydration reservoir and sawyer filter, as well as extra rain layers – basically the stuff I don’t want in the main compartment because it’s wet or smelly.

The rear pocket is large enough for me to store all of my wet gear, such as a tarp, tent fly, or wet rain gear, my water filter, and smelly items like a wood stove that I don’t want inside the main compartment. I also use this pocket to store snacks and extra thermal layers, so I don’t have to open the main compartment during the day when I’m hiking.

The hip belt pockets have waterproof zippers and are large enough to store a small camera, a few food bars, or AquaMira bottles. While I do wish the pockets were positioned a little further forward on the wings of the hip belt so they are more reachable, it’s not a showstopper.

Backpack Attachment and Compression System

The 3400 has a two tiers of side compression straps that can be used to attach gear to the outside of the pack. A bottom compression strap runs horizontally outside each water bottle pocket, while the upper strap is oriented at a diagonal to bring the load closer to the wearer’s back for better load-to-hip transfer.

A Y-strap loops over the top of the pack and is useful for securing bulky items like a foam pad or tent body
A Y-strap loops over the top of the pack and is useful for securing bulky items like a foam pad or tent body

In use, I decouple the bottom compression strap over the water bottle pocket because I find it interferes with getting water bottles into the side pockets when I’m wearing the pack (it confuses my hands). Instead, I route the webbing out-of-the-way through additional buckles on the back of the pack which can be used to attach more gear, like snowshoes. HMG sells extra webbing straps for this purpose as an add-on although there’s nothing preventing you from rigging up some cord and cord locks instead.

In addition to the roll top, which provides excellent top compression, there’s a Y strap that runs from the front of the pack (between the shoulders), over the roll top, and attaches on the back of the pack. This strap is great for securing bulky items like a foam pad, rope, or tent body to the top of the pack.

Backpack Frame and Suspension System

Both the Hyperlite Mountain Gear 3400 Southwest Backpack and the 2400 Southwest Backpack have a lightweight frame system called frame stays instead of a rigid wire frame or framesheet made with hard plastic. The stays come preformed but can be easily bent to match your physical characteristics better.

The 3400 has two aluminium frame stays that slot into stay pockets behind the shoulders
The 3400 has two aluminum frame stays that slot into stay pockets behind the shoulders

The frame stays are two aluminum rods that slot into stay pockets on the inside of the main compartment and terminate inside the hip belt. The stays keep the back panel behind your shoulders rigid so it won’t collapse on itself. They also to help transfer some of the pack weight off your shoulders and onto your hips, since the bottom of the stays terminate inside the 3400’s hip belt, which is sewn directly onto all of HMG’s packs. The sewn-on hip belt is one of the main reasons why HMG’s packs carry so well. Shop around. Very few ultralight pack manufactures have a hip belt that is so tightly coupled with the pack body. It makes a huge difference.

The hip belt of the 3400 Southwest is covered with padded mesh, but not overly padded which is what I prefer, with a beefy front buckle for durability. The shoulder straps also have light padding, with sewn-on daisy chains that make it easy to add accessory pockets, like my camera pocket (shown), or navigation devices to the straps.

Daisy chains sewn on the front of the shoulder pads make it easy to attach exra pockets or navigation instruments
Daisy chains sewn on the front of the shoulder pads make it easy to attach extra pockets or navigation instruments

When packing the 3400 Southwest, you need to be cognizant of the fact that the pack’s back panel and frame stays end at the top of your shoulders and do not provide extra rigidity for gear stored in the extension collar. Heavy items, like food bags, should be packed towards the bottom of the pack and as close to the back panel as possible. This is doubly important because HMG does not put load lifters on their backpacks because they don’t have full frames (load lifters on frameless packs have marginal utility), and there’s no way to tilt your load forward if you’ve packed it so it pulls your center of gravity backwards.

When I pack the 3400, I put my sleeping bag stuffed in a dry sack at the bottom of the pack and then stack my food bag in top of it, stacking my hammock and other heavy items up the back panel as I go. I stuff lighter weight insulating layers and clothing behind the heavier items to hold them in place, and then put my lightest items in the extension collar (mainly clothing and personal effects). I then use the pack’s roll top to compress the items in the extension collar and shrink the volume they require. This weight and volume distribution provides the best load control since heavy items are located near my hips and there’s a direct transfer of kinetic energy from my core to items located just above the small of my back.

Cold and frosty morning on the Maryland AT with the Hyperlight Mountain Gear 3400 Southwest Backpack
Cold and frosty morning on the Maryland Appalachian Trail with the Hyperlite Mountain Gear 3400 Southwest Backpack


The Hyperlite Mountain Gear 3400 Southwest Backpack is a bomber multi-day backpack geared for tough adventures that will rip most other ultralight-style pack to shreds. It you’re rough on backpacks, but still want one that only weighs two pounds, the 3400 Southwest pack probably has your name on it.

Equally at home on the trail as well as off, the 3400 Southwest Backpack has the extra volume required for longer or more technical trips when you need to carry extra gear or clothing. I use mine for long section hikes on the Appalachian Trail when I need to carry extra food, shoulder season insulation, or cold weather hammocking gear that won’t fit in the smaller volume Hyperlite Mountain Gear ‘s 2400 Southwest Backpack that I use for off-trail hiking and weekend backcountry fishing trips in New Hampshire’s White Mountains.

While highly water-resistant as a benefit of its hybrid cuben fiber construction, the value of the HMG 3400 Southwest Pack lies in its unique combination of low weight and durability without skimping on functional features. You don’t need to compromise on durability if you want a lightweight backpack. A backpack is a big gear purchase. Get one that is designed to last. Nuff said.


  • Taped seams and needle holes make the pack nearly waterproof
  • White color makes it easy to find gear inside pack
  • Roll top closure and side straps provide good compression
  • Side water bottles are reachable and replaceable while wearing the pack
  • Bomber tough against puncture or abrasion by aggressive vegetation
  • Side and front external pocket have reinforced bottoms and drain holes
  • Fantastic load to hip transfer
  • Daisy chains sewn into shoulder straps make it easy to attach accessories
  • Good range of sizes available for people with short torsos, including women


  • More expensive
  • White color is quickly discolored by dirt and grime
  • Center ice axe loop is awkward to use; no shaft attachment provided

See Hyperlite Mountain Gear for complete product specifications.

Disclosure: Philip Werner purchased this product with his own funds. 

Editor's note: Help support this site by making your next gear purchase through one of the links above. Click a link, buy what you need, and the seller will contribute a portion of the purchase price to support SectionHiker's unsponsored gear reviews, articles, and hiking guides.

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  1. Philip, when using this pack, do you use a pack liner at all? I’ve been using my HMG Windrider, but others ( who don’t have this pack) insist that I should be using a pack liner. I just keep my quilt in a dry sack, never have used a liner. I have not had any issues with water getting into the pack. Just wondering if you or anyone else has.

    • I line mine with a trash compactor bag and I have had some leakage in the 2400 from a leaking hydration reservoir in the rear pocket. HMG does say that their packs are not waterproof, just water resistant, and they also sell a 44L pack liner that only weighs 1.8 ounces, I believe.

      As a side note, I used that trash compactor bag recently to insulate myself (with a foam pad) from a wet hammock underbody when my tarp stakes pulled out on a cold, wet, and stormy night on the AT, so it has multiple uses. This is also not the first time, I’ve used a pack liner in an thermal emergency.

  2. Hey Philip,

    How do you find the padding in the back of the pack? It is easy for things to poke you and can you feel the stays on your back?

    • You can feel stuff if you pack it wrong like any frameless pack without an integrated back panel. Just keep the angular stuff away from the back. I can’t feel the stays though.

  3. You will need to line yoiur pack as the fabric is only “waterproofish”, certainly not 100% waterproof. I have no idea of the hydrostatic head. I did, in fact, have significant water leakage over a 12 hour heavy rain hike. I have used several versions of this pack (I tested a pre-production front pocket for them) and the fabric is decently abrasion resistant but certainly no more than 210 Dyneema Gridstop. Probably less if you are using the 70D version of the hybrid cuben v.s. the 100D. What is an issue, however, is the cuben tape that is used to waterproof the seams. It doesn’t take much for it to start to pull off. The belt needs to be wider and the shoulder harness more padded. They did away with the belt tensioners a couple of years ago which, in my opinion, affect the carry negatively. Having said that, comfort with packs is a very personal thing.

  4. My wife and I have an older Ice Pack, which has a integrated removable bivy pad in a pocket in the back panel that protects the wearer from things poking. We’ve never noticed any discomfort. Not sure whether that option is available for this pack. Although the website does state for both the IP and the SW that there is a “1/4 foam back panel pad”, but I think it used to be described on the Ice Pack as a removable bivy pad. I really like the ability to have a included emergency removable bivy pad, whether on a mountaneering or a hiking pack, and I hope that feature has not changed, but maybe others can chime in or you can contact HMG to confirm. We love our pack!

  5. know there are a lot of variables so I don’t expect a scientific answer, but as much as you deal with both different pack sizes, I thought you may have an intuition. I would like to go with the hyperlite mountain gear 2400 if it’s plausible but I’m having trouble knowing whether it will work for me in the fall when I do MOST of my backpacking. I have their 8.5×10 tarp, a borah net bivy, zpacks 20 degree quilt, a cook kit that fits inside my 475ml MLD mug pot, and I carry water in water bottles in side pockets. Just from that info can you make a good guess which size pack I’ll be happiest with? I’m pretty new to the UL scene and don’t want to over-do it on my downsizing, but I really like the idea of a backpack that never gets above my head. it looks like the 2400 is the only one HMG offers that will never threaten to peek up there.

    • Get a box. Put all your gear, water, and food into it. Measure the cubic inches it takes up. It’s the non-consumables that take up space. The 2400 will likely work for you, but this way you’ll know for sure. (they also have a return policy)

      • I own the 3400 Southwest by HMG, with the top opening rolled all the way down it’s the same size as the 2400, a few extra ounces for the 3400 but the room is there if needed. Comfortable pack.

  6. Trying to decide between this pack and the Zpack Arc Blast. Care to comment on pros and cons of each as well as your personal preference? Thanks,

    • The HMG pack is heavier because it’s more durably built. Less to fail, and no mesh pocket to rip up. What you see is what you get too. No “extra” customization charges, but then again, there’s no extra customization. The blast is a fine pack too, but I find the external frame to be annoying when I hike off-trail. YMMV.

      • Phil,
        From your comments can I assume you prefer to solid fabric of the SW to the mesh of the windrider? Also is the HMG a heavier thickness of the cuben fiber and that is what makes if more durable or better stitching, etc,?

      • Exactly. I like a solid pocket because I destroy all mesh sooner or later (usually sooner).
        The HMGs are more durable because CF is more durable than say Robic (nylon), which other manufacturers like Gossamer Gear are using. I haven’t been able to puncture, rip, or abrade one of my HMG packs, but I have a closet full of robic and silnylon packs with all of those injuries.

  7. Hi Phil, as a first UL backpack, what would you use to define the choice between this and a GG Mariposa? Thanks for the great articles!

    • Durability primarily. I used a Mariposa for six years (I own several) and got sick of repairing them or replacing them when they got ripped up. I love the Mariposa, but it’s too fragile for me. The Mariposa does have much better external pockets for tent campers though, though. It really depends on what you want. I like carrying two bottles on two different sides, and the HMG packs let me do that. They’re really very different packs.

      • As a new owner of a HMG 3400 Southwest – I can also attest that they are not waterproof. Significant leakage during 5 hrs of heavy rain and hail. I plan to try some seam sealing around the shoulder straps and bottom of external pockets to see if this reduces water ingress (I live is Scotland so it is guaranteed to rain again soon). Still love the bag though, durable, simple and comfortable.

  8. How do think this pack would do carrying a BV 450? I assume it would be placed vertically above your sleeping bag and might be uncomfortable against your back.

  9. Phillip,

    I just bought the 3400 Windriver and hiked 37M (2 days) on the AT… ending at the desolate… Notown, VT.

    I totally loved this pack. At 25 lbs… my Hennessy Hammock system (3-Lb/6-oz), stove, fuel and cookware (1-lb), complete Sawyer hydration/filter and water bottles (1-lb),
    40-degree down bag (1-lb), and sleeping pad (1-lb) made up my lightest ultra light pack I ever carried.

    The pack fit perfectly on my hips and it didn’t contribute to a sweaty back.

    Having said the above, after reading the thread on your blog, I think I’ll get the pack liner.

    The only inconvient aspect of this pack are the 2 side mesh pockets which I carry a water bottle in each. In one I carry a 32-oz light weight Nalgene bottle (to carry 6 servings of liquid UCAN – I’m Type 2), and a 32 oz light weight water bottle in the other side mesh pocket. I don’t know how to grab either bottle without swinging the pack off both shoulders and onto one. ANY THOUGHTS on how to make this less inconvenient?

    Thanks much…


  10. Gary, I have this pack and I cannot get the bottles out either. I could not find any other pack that was as comfortable so I found a work around. My husband drilled out (using a special drill bit) a hole in the Gatorade bottle cap and we slid a hydration hose into the bottle. I clip the hose to my shoulder pad and drink just as though it is coming from a hydration bladder. We had to place a small rubber grommet in the hole in the cap. We also used a small brad to press a very small hole in the cap to alleviate the vacuum issue. A few people have seen this and have asked how we did it. I usually just give them a cap. If you wish, I can send you either a large Gatorade bottle top or a Smart Water bottle top for you to use. If you want spares, then you will be able to copy the one I gave to you. Maybe Philip can give you my email so that I can get your address? Please note, this was not my original idea, I saw it on one of the backpacking forums. I just don’t remember which one.

  11. Hi Philip,

    I’ve posted several places looking for advice on deciding between a Windrider 2400 or 3400 pack. I’ve tried a ULA Ohm 2.0 and Circuit, but never in winter. Most if my trips are 3 season 2-3 night trips, with a base weight of 13-15 lbs. However I hope to do longer summer trips and a weekend snow camp or two in the next few years. A winter kit might push 18-20 lbs

    I hate to buy a pack that’s too big for most of my trips, but HMG tells me the 3400 compresses well. I also heard the y strap on top will hold a bear canister, which makes me think the 2400 will do fine.

    Should I size up for those hypothetical trips or stick with the 2400 and size my kit to fit? Having used both I appreciate your feedback.


    • Impossible to say with what little info you’ve provided. My winter gear list weighs 27 ponds and fits easily in a 3400 but it’s not really as compressible as they say. I use the 2400 the test of the year. Read my post tomorrow and then decide. You’ll understand.

      • Hi Philip and thank you for the reply. I will look forward to your next post. Just read about glop – definitely good stuff.

        Since you sorta alluded that more gear list info might help, here is a summary of my current backpacking kit for SoCal:

        ULA Ohm or Circuit (32-41 oz)
        Hammeck hammock, HG Cuben tarp, huggers and suspension (25 oz)
        HG UQ and HG or EE TQ (33-43 oz – one set over 40 and one 15-40F)
        Clothes for sleeping and weather changes (27-40 oz – depending)
        Alcohol cookset and Ti or AL pot and mess kit (5-10 oz – depending)
        Other essentials: Electronics, Fire and knife, hygiene and safety (40-50 oz)

        Food – typically 2-3 days using Ursack (I have a BV450, but haven’t used it)
        Water – varies a lot since we are in a multi year drought
        (I’ve typically started w/ 7-11 lbs of consumables, and usually bring home a little).

        Most of my trips are SoCal desert and local mountains in our 3 seasons (Fall-Winter-Spring), and higher mountains in the summer. Mountains sometimes have water and I use dehydrated food (sometimes glop) for 3-4 days max in my recent history. If no water then I need to carry it all, so sometimes bring real non-dehydrated food since I’d have to carry in the water anyway – those are typically 2 days. I got the Ohm most recently and it’s fit everything I needed so far, and things like a helinox chair that I wouldn’t take on a multi-day trip.

        I have not done any snow camping recently – when I did I had a 7lb Gregory pack, ~5lb Kelty Tent and a 3 lb sleeping bag. I know I have to pack more winter clothes and the warmer quilt set to go down to the teens, but that’s my limit for now, and it will be rare. When I can’t hammock, I replace the hammock/tarp/UQ with a Tarptent Notch and Thermarest NeoAir Xlite.

        As I said originally, I am normally a 2-3 night camper, but plan to stretch that in the Sierra this summer (maybe 5 night). I also hope to do at least a section of the JMT and/or join my son’s scout troop at Philmont in 2018 or 19, which could be a 7 or 12 night trek (presumably with some resupply).

        I’ve heard and read great things about the HMG packs and want to give them a try now. My gut tells me to get the 2400 and use it now, trying to keep my kit small as I extend my range. I could re-invest in a larger pack when the time comes. If the HMG carries as well as some have suggested, I might sell one of my ULA packs.

        Thanks again for your website and regular posts, and for your consideration in helping me and others like me who want to hike more.


  12. Phil, after 10 years my Golite Pinnacle needs to be replaced. Have you used or do you have thoughts about the Southwest 4400? Thanks.


    • Not a big fan of HMGs 4400 packs. They don’t have load lifters which makes them hard to adjust with big loads. It’s not a problem with the 3400s though. I have a review on the website. Search for 4400.

  13. hi Phil,

    Can you compare the HMG 3400 vs the ULA Catalyst for climbing Mt Rainier carrying ice axe, crampons, helmet, etc? Curious which carries 40-50 pounds the best for mountaineering.

    • I’d go with a 4400 HMG. Preferably one without any pockets. Much easier to use the external attachments to carry awkwardly sized pieces of gear. They can both carry the load, but the fabric of the HMG is stiffer, so your load can in essence become part of the frame if packed tightly.

  14. Hi Philip,
    I recently ordered an HMG Southwest 3400. I thought it would best meet my needs in a lightweight durable pack that can carry up to 35 pounds comfortably. Unfortunately that hasn’t been my experience and I’m on the verge of sending it back. When I first loaded it up with over 30 pounds and walked around my neighbourhood, I found it uncomfortable. My shoulders were sore, and my neck ached, no matter how I adjusted the sternum and shoulder straps. So, now I have tried it with less weight, around 25 pounds, and now only one shoulder aches and much less neck pain, but some neck pain when I use my poles. I did not have pain using my previous backpack an MEC eos (Canadian backpack)with a very padded and comfy waist belt and shoulder straps.
    I do love the weight and general design of the pack— do you have any suggestions on how I could deal with these issues? Or should I return it? Thanks,


    • Is the torso long enough? If your shoulders are sore its probably because the hip belt isn’t on your hips.

      • I measured my torso at 19″, and bought the Large, based on its’ recommended torso length of 19-21″. I compared it to my other packs (MEC Eos and an Osprey Exos 38 Large), and the straps seem to be about an inch higher than on my other packs (rough estimate looking at the space from the hip belt padding to wear the shoulder straps attach). If anything, I would think it might be a little big, but I don’t think that should cause shoulder pain. When using it, I even released the shoulder straps significantly to rest most of the weight on my hips, but then I find the bag sways alot, and I still have some aching. I’m going to try again later this week.

  15. Hi, I have been looking at the Granite Gear Crown2 60 as well. Yes, they have many differences, but each seems terrific for long distance trekking, especially for winter. If you had to choose, which would you choose and why..Thanks

  16. Hey Philip,

    Sweet review man, some great and thorough information here. Thank you for it. I am almost ready to pull the trigger on the Windrider 3400 but I have some questions about the materials of the external pockets between the Southwest/Windrider. When you see other people with holes in their mesh pockets, was it on the big main back pocket or the side water bottle pockets? I ask because I am thinking about costom making my pack to have the side pockets as Dyneema and the main pocket mesh. I woul like to have mesh as the back pocket so I can dry out gear while I hike but Dyneema for the side pockets that are most accessable to passing tree branches, bushes and rocks that would likely tear em apart if they were mesh. Do you think this plan would work? Or should I just go full Southwest for ultimate durability?

    Cheers man,


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