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Our mountaineering experts have tested 30 of the best mountaineering backpacks over the last decade. After buying 10 of the latest and greatest, our field testers hauled them into the mountains. We scrambled up remote alpine peaks, swung ice tools on steep waterfall ice, and set out for multi-week expeditions. We tested these packs all throughout North America, dragging them up summits in California, Alaska, and multiple ranges in Canada. Our group of test packs has been used tirelessly for months on end, through all seasons. The result? A comprehensive, unbiased, and honest review, objectively comparing and scoring products — all summarized and packaged here to help guide you to your ideal pack for your mountain adventures.
Editor’s Note: This review was updated on October 28, 2022, with information about some Arc’teryx and Osprey pack updates. These individual reviews were also updated with detailed information on each pack’s revisions.
As of October 2022, Osprey tweaked this pack with recycled NanoFly fabric and removable gear attachment straps. We’re linking to the updated model.
Once again, we’ve chosen the ever-impressive Osprey Mutant 38 as our favorite mountaineering backpack. This pack seems to get better with every mutation, with improvements to utility, versatility, durability, and climbing comfort. This is a pack that can morph from a gear-hauling beast to a light and nimble summit pack in mere moments. It has an excellent suspension for heavier loads and logical and useful climbing features for technical pitches.
Many climbers still retain some skepticism toward Osprey as a manufacturer for technical climbing packs. We did, too. Some of their packs have too many features and so many straps that they slap you in the face when you’re on the hardest part of the climb (classic). This pack has more features than some, but it can be slimmed down to become comparable with the simplest and lightest packs in this review. Overall, this is an excellent update to an already awesome mountaineering pack. Be sure to also check out the Osprey Mutant 52 which fills a void in our backpack quiver as the most comfortable pack of its size. The Mutant series is now relevant to longer and more complex, colder, or more gear-intensive climbs.
The Black Diamond Blitz 28 is an excellent and affordable addition to your mountaineering pack quiver. This pack is simple, light, and small — making it an excellent companion on routes where you are pushing your grades and trying hard. This is the only pack tested here that we’d consider taking into the mountains as well as on long multi-pitch rock routes, using it similarly to a small on-route climbing backpack like the old Black Diamond Bullet or Petzl Bug.
There are numerous issues with this pack, notably the durability and its lack of versatility for all types of mountaineering. It’s unlikely you would want to take this pack ski mountaineering, though you may enjoy its lightweight simplicity for a mellow day of backcountry skiing. And you’ll want to be careful how you pack the bag, so you don’t create too much abrasion from protruding objects. In general, this backpack is noteworthy for filling a valuable niche at a decent price.
Frame: Sewn-in foam, single stay | Measured Volume: 50L
REASONS TO BUY
REASONS TO AVOID
The Hyperlite Prism would be number one if it could manage warm, humid environments better — but we’re not saying that Hyperlite needs to address these issues. The benefits (and value) far outweigh any sweaty back issues. It just means this may not be your quiver-of-one backpack. The Prism has completely refracted our idea of how comfortable a technical climbing backpack can be and how fresh we can feel after a long and heavy haul to basecamp. The simple design blows our minds. This is a pack chosen by many guides who just can’t afford to beat up their bodies anymore with heavy, cumbersome, awkward, and overall damaging backpacks. The price in dollars is much more affordable than the price we pay in injury to our bodies.
So that gets to the only real drawback to HMG packs in general: the price tag. But if you’re getting out a lot in cooler alpine environments, the Prism is an excellent investment to make for your longevity and enjoyment. This pack is optimized for technical alpine climbing with a crampon pouch, simple side straps, a low-profile wand/picket pocket, and a removable lid. Versatile, durable, comfortable, high performance, and kind to our bodies — all you need in a long-term climbing companion.
The Speed packs from Black Diamond are another series of packs that we love — one for all of your moods or objectives. We think this 40-liter version of the Speed hits the sweet spot for versatility and carrying comfort. This is as close to an all-star pack-of-all-trades as we have ever found and for an excellent price. The features are simple but complete and will handle any of the tools you need in the mountains. The materials are durable yet lightweight.
There are just a couple of troubling features, though they aren’t deal-breakers. The top strap slides through to either side, presumably to allow you to extend one side more than the other for bulky, light items. However, the bottom strap doesn’t extend similarly, so we didn’t find this feature useful. And the ice tool attachment secures both tools at once, another feature we don’t like. We prefer being able to deploy one tool at a time without messing with the other one. But all said, this is an excellent, durable, versatile, simple, and very affordable mountaineering pack that we highly recommend.
The Gregory Denali 100 shines for its comfort and versatility on expeditions. We appreciate the Denali for how comfortably it sits on the back and the fact that it does not impinge your view or range of motion in the places where it rises above your head. We also like the snow-specific features since most packs of this size are likely to encounter snow at some point during an expedition. And, when packed well, it feels secure and streamlined while still allowing easy access to items via large zippered sleeves and pockets.
It should be noted, however, that this isn’t a featherweight pack meant for a wide variety of expeditions. And some of the features feel fiddley, like the velcro attachment for the ice axe, which is connected to the buckle for the side strap. Bottom line, Gregory built it for its namesake Denali, and it does that job well.
Hauling a sled during a round of testing with the Denali 100.
Credit: Lyra Pierotti
The Bugaboos were a great testing ground for the updated Mutant 38.
Credit: Hjordis Rickert-Zeugswetter
Why You Should Trust Us
Traveling and climbing mountains for years, our team of experts has used and abused a lot of packs. They’ve seen the changes in technology, design, and features and know exactly what works and what’s just marketing hype. The packs in our review have been worn through all manner of terrain and temperatures, on overnights, summit bids, approaches, and descents. From light and fast to heavy and extended, we present an unbiased and critical assessment of the best options for your next mountaineering pack.
Our testing of mountaineering backpacks is divided across five different metrics:
Versatility (30% of total score weighting)
Weight to Volume Ratio (20% weighting)
Comfort (20% weighting)
Durability (15% weighting)
Features (15% weighting)
This comprehensive and detailed review is led by Lyra Pierotti, a certified AMGA Rock Guide and AIARE Avalanche Course Leader. As you might imagine, Lyra spends a ton of time in the mountains and carrying a pack. She’s taken on peaks all over the world, from Alaska to Argentina, and also helps coach others to achieve their mountaintop aspirations as an NSCA Certified Strength and Conditioning Specialist (CSCS). Her passion for this work runs deep and, with more than a decade of experience, she’s an ideal expert to spearhead this review.
When you’re working hard to get to a summit and back down safely, the last thing you want is a faulty pack.
We love the perfectly conceived features of the Hyperlite Prism.
Getting ready to explore up high with the Alpinisto pack.
Analysis and Test Results
This is a review of mountaineering backpacks for technical alpine climbing. The packs are equipped with features useful for everything from traditional mountaineering with ice axes and crampons to alpine rock climbs, ice climbs, or even ski mountaineering. The main difference between these packs and those found in our best backpacking backpack review is in the feature set. Mountaineering packs are made to carry crampons, ice axes, ice tools, ropes, and potentially skis. They also vary in shape, size, and carrying comfort.
Mountaineering packs are often identifiable by their svelte exterior. They sport minimal straps or excess material that can whack you in the face when it’s windy up high on a ridge. They are more streamlined and hug close to your body to improve mobility and climbing comfort, and they are made of light but durable materials. They don’t have lots of pockets, straps, access points, or beefy suspensions.
The ideal alpine climbing pack for most venues in the U.S. should be relatively easy to overstuff with several days worth of food and basecamp necessities. Then it must be able to slim down for technical climbing. We want a pack to be streamlined for climbing, but we don’t want to be so beaten up from carrying an awkward load to basecamp that we are aching during the climb itself.
Testing mountaineering backpacks in the Pacific Northwest. Another great day at the office.
Credit: Ryan Thompson
A Note on Our Mountaineering Backpack Selection:
We selected a wide range of packs for this review. We recognize that alpine climbs come in all shapes and sizes and offer a glimpse into some of the best packs for everything from in-a-day alpine missions to multi-week expeditions. Most of the packs in this review are in the 30 to 50-liter range, which is a great all-around size. You will find a few outliers, however, notably the Gregory Denali expedition pack and some “tweeners”, as well. All this is to say — there are a lot of caveats and tradeoffs in choosing a mountaineering pack, so be sure you’re selecting the right tool for the task. Each review thoroughly discusses the best applications for each pack to help point you in the right direction for your climbing passions.
Our performance scores aim to shake out the best packs from the mediocre ones. Just like cream, the best rise to the top of the chart. These performance scores, however, do not take price into account. Rather, we want to know what the best packs are without biasing our assessment due to the price tag.
After we figure out which packs are our winners, it’s time to figure out just how much you want to spend and how much versatility your pack needs to provide. The top-scoring Osprey Mutant 38 offers excellent value with its performance that soared above the rest at an almost shockingly low price. It’s truly an incredible pack. The Black Diamond Speed 40 excels at everything from laidback crag days to hardcore summit bids, and it can significantly cut back the number of packs you might need in your collection, also for a more-than-fair price. The Black Diamond Blitz 28 is more optimized for shorter missions and while on-route, but the price can’t be beat if it fits your needs.
Fast and light alpinism on Mt. Baker’s North Ridge.
Credit: Yoshiko Miyazaki-Back
Our testers demand a lot from their climbing packs. We want them to be comfortable hauling loads on the approach but not hinder our movement once we’re on route. We scored each pack based on its ability to adapt. Versatility also influences whether you’ll have to buy three packs for all your adventuring needs or if you can get away with one Jack- or Jill-of-all-trades. Or pack-of-all-trades.
The Osprey Mutant 38 took the cake when it came to versatility. It earned top scores by remaining impressively comfortable when hauling heavy loads and is able to shift effortlessly onto technical terrain. If you prefer something a little simpler, however, you might consider the Black Diamond Speed 40.
There’s some reference to Goldilocks in this photo of the Osprey Mutant 38 (left) and 52.
Credit: Lyra Pierotti
If you find that you love the 38-liter pack size, but you consistently stuff it to the brim, give a look at the next volume up from Osprey, the Mutant 52. Although it doesn’t climb on route quite as well as its smaller cousins, the 38 and 22-liter versions, it does very well on longer trips and more complex, gear-heavy climbs.
Some packs allow you to remove the framesheet to reduce weight or to use as an emergency foam sleeping pad. For larger models, this can be an excellent feature to know about. We especially liked this feature on the Gregory Denali 100 since you will want to take a foam pad with you on summit day on most high-altitude expeditions. This pad is integrated into the Denali and means one less item to add to your summit pack.
The removable foam pad in the frame of the Denali means one less thing to carry on summit day, since we tend to carry a foam pad for safety on big alpine summit pushes.
Gearing up for an alpine rock ridge with the Gregory Alpinisto LT 38.
Credit: Maryanna Brown
Weight to Volume Ratio
Mountaineering is a physically and technically demanding sport. It forces you to carry everything necessary to survive in a harsh mountain environment with you at all times. It’s a delicate balance; carrying too much weight or a load that’s too bulky can compromise your balance on technical maneuvers or deplete your energy stores. This means the weight of your pack and the volume it can comfortably carry is of the utmost importance.
Stripped Weight — Sometimes you may want to consider the stripped weight of a pack. This is the weight of the pack minus all of its removable components, such as a lid (aka brain), hip belt, or framesheet. This measurement is decreasing in importance as more and more pack manufacturers are eliminating the lids, minimizing hip belts, and sewing the framesheet in place. That is to say, more and more often, the baseline pack is the stripped-down model. We have adjusted some of our scores to avoid penalizing packs that have more features but can still be stripped down to minimize weight.
All loaded up with the Hyperlite Prism.
Credit: Lyra Pierotti
We list each pack’s weight-to-volume ratio. But we didn’t take the manufacturer’s word for it. We measured the volume ourselves with the help of hundreds of ping-pong balls to get an apples-to-apples (or pings-to-pongs) sense of what each pack could handle. We also measured the weights ourselves with a digital hanging scale.
Due to the differences in volumes between packs, it’s possible that a smaller model made from heavier materials could still be lighter than a more substantial contender built from lighter-weight materials. To account for this, we use a weight-to-volume ratio to help us better compare the pack weights irrespective of pack size. We measured the weight of the whole pack in grams (g) and volume of the main compartment in liters (L) (note: we did not include the volume of the lid or any pockets because loading pockets can throw off a pack’s balance). This helped normalize our measurements across all manufacturers because some report volume including the pockets while others do not. This score shakes out when we get to features, where packs with lots of pockets scored higher in an objective sense. If you hate pockets, you can look with skepticism upon a highly featured pack.
The Speed 40 from Black Diamond gobbled up the gear from our official Test Load and carried it like a dream.
Credit: Lyra Pierotti
For a more realistic test, we also assembled a sample kit for a weekend of summer alpine climbing. We then tried to pack this gear into each of the packs. Although this test was less useful for the expedition packs, which gobbled up all the equipment and then some, it gave us an intuitive visual way to compare practical volume. It also helped us to evaluate attachment systems for crampons, ice axes, poles, ropes, helmets, etc.
The Blitz 28 from Black Diamond is streamlined and low profile for excellent performance on technical routes.
Credit: Jeffrey Martinez
For this review, we measured the weight of the Osprey Mutant 38 without the lid. Due to the increasing number of packs that forego lids, we felt the added weight was an unfair penalty to the Mutant, especially since the lid can be removed and the FlapJacket deployed. For the 52-liter Mutant, we left the lid on because it is a larger pack designed for more carrying capacity. The Black Diamond Blitz 28 stole the show in this category for being impressively lightweight for its volume. Though limited in scope, if you’re looking for the lightest on-route pack, this might be the one.
There are two important components to mountaineering pack comfort –comfort on the approach and comfort on the climb. Smaller packs with flexible (or minimal) framesheets tend to be more comfortable on technical climbs than larger, beefier packs. Larger packs, in contrast, usually have more substantial suspension systems, framesheets, stays, and padding. These tend to make the approach more comfortable than an overloaded fast-and-light pack but can feel stiff and cumbersome on technical rock and ice routes.
We are seeing more and more mountaineering backpack models with flat back panels and simple suspension systems. Pack manufacturers are sometimes eliminating the lid and even the load lifter straps on top of the shoulder straps. At first, we were skeptical, worrying that this design change would boost climbing performance at the expense of comfort on the approach. As we found out, however, this is not entirely true.
First, let’s point out that the more traditional Osprey Mutant 38 is still the most comfortable with heavy loads. It has a minimal frame but can carry up to 50 pounds with ease (as easy as carrying 50 pounds on your back can be, anyway).
Taking in the views down glacier in the ever-comfortable Osprey Mutant 38.
Credit: Hjordis Rickert-Zeugswetter
Let’s also look at the impressive performance of the other top category scorers, the Hyperlite Prism and Osprey Mutant 52. The Mutant 52 is essentially a scaled-up version of the 38. But the Prism is impressively simple. There is only a single removable stay in the center of the back panel, and that panel is sewn in place to the material of the pack. The hip belt is removable and rests relatively flush against the pack, and there are not load lifter straps — the brain attaches instead to the uppermost part of the shoulder straps. Very interesting. Noticeable with the Prism is that it has a relatively narrow profile for a pack that carries around 50 liters capacity. The light weight, firm foam, and narrow profile of this pack add up to make it one of the most comfortable we’ve tested, whether under heavy load or trimmed down for fast-and-light ascents.
The Hyperlite Prism is among the most comfortable packs we’ve ever tested.
Credit: Caitlin Ames
To better help us understand why this flat back panel design in climbing packs works, we consulted with a physical therapist and climber who helped us make sense of it. To summarize, traditional packs with lumbar support push your spine into extension, which is a strong structural position for those unaccustomed to carrying a backpack. It doesn’t work as well, however, for fit alpine climbers more accustomed to carrying moderate weight on their backs. Instead, that backpacking pack design locks our bodies in an extended position, making it harder to flex and rotate. Greater mobility, in contrast, allows us to fully exhale, rotate our torso more thoroughly, and tilt our pelvis backward, making high stepping much easier. This means you have to fight against the shape and structure of the pack much less — thus saving energy over the course of a long climb.
Another critical reason why these simple pack designs seem to work is the concurrent increase in ultralight, durable climbing equipment — particularly sleeping pads, sleeping bags, and shelters. Add all of this together, and we can go further while carrying less weight.
Getting a peek at the structural issues that ultimately made the Arc’teryx Alpha AR 55 score lower for comfort. Notice the slack in the backpanel? The support would get sloppy over the course of a day’s climbing or skiing, ending up feeling awkward and cumbersome.
Credit: Lyra Pierotti
Offwidths and mixed chimneys, bushwhacking, careless crampon use, stuffing bags to their gills — alpine climbing can subject a pack to all sorts of wear and tear. But when our testers are in the mountains, they like to focus on climbing instead of babying their equipment.
Fabric durability is commonly assessed using a “denier” number, which is the linear mass density of fibers. In other words, a higher denier number usually denotes a thicker, more durable fabric. A lower number fabric will be thinner and typically lighter weight. This rating, however, doesn’t tell the whole story. The primary durability issue for mountaineering backpacks is their fabrics’ abrasion resistance. Manufacturing techniques, terms, and treatments can make this tricky to parse out.
Climbing the NY Gully on the north side of Mt. Snoqualmie, Washington. Mixed rock and ice means more opportunity to scrape your pack.
Credit: Lyra Pierotti
Hyperlite Mountain Gear packs are made of Dyneema Composite Fabrics (formerly Cuben fiber), which are exceptionally lightweight, strong, waterproof (before stitching), and UV resistant. To improve resistance to abrasion, their backpacks feature Dyneema Composite Hybrids, where more abrasion-resistant face fabrics are laminated with the Dyneema Composite Fabric backing. The Hyperlite Prism is an exceptional example of the company’s craftsmanship.
Many pack manufacturers use fabrics with a lower denier on the sides and top of the pack to save weight. Higher denier fabrics are placed on high-impact areas like the pack’s bottom and crampon pouches. However, we find that when climbing in typical alpine terrain, the sides of the pack do get scratched up. The only part of a pack that really seems to not see abuse is the part that’s against your back.
Is your pack durable enough for the unexpected maneuvers you might pull in the mountains? Here, we’ve threaded our skis under a shoulder strap for a quick boot up to the ridge.
Credit: Robin Pendery
Of more concern in the durability department is the strain put on specific areas of the pack due to design and construction. We inspected each model for notable stress points and any stitching that looked like it might give out over time. Will the compression straps tear out of their seams under bulging loads? Does that initially cushy hip belt wimp out over time? Imagine a worst-case scenario: you arrive at the belay, clip your pack to the anchor by its haul loop, only to have that rip out, and your pack fall hundreds of feet to the deck.
The Patagonia Ascensionist 55 is a durable pack — after lots of field testing, it definitely showed some wear and tear, but there weren’t any notable stress points. Our top scores, however, go to our overall winner, the Mutant 38, and the Arc’teryx Alpha AR 55, which didn’t score well in many other metrics but did very well in this one for its unique and durable fabric.
The durable double bottom is much appreciated on the Black Diamond Speed 40. But note that sometimes security is part of durability – these sharps are stashed so they won’t move in transit and create any puncture holes.
Credit: Lyra Pierotti
Simplicity can be a great feature in a climbing pack. Well-designed alpine climbing packs are more streamlined than your standard backpack. Unnecessary features add weight and complexity while only amplifying the number of things you can break. For this reason, we gave points to packs that provided only the features necessary to complement the design of the pack.
On the flip side, as long as the pack features are useful and don’t detract from functionality, we rate the pack highly in this metric. As such, Osprey hits it out of the park with the Mutant 38. Osprey has a long history of making packs with excess features, often to the dismay of climbers who want a simple cylinder with minimal straps. The Mutant has both surprised and pleased many climbers and mountain guides, allaying years of accumulated skepticism with the well-designed, durable, versatile, and impressively comfortable Mutant.
The Mutant has a collection of well thought out features, from gear loops and streamlined side straps to pick holsters and T-bars that allow you to deploy your axe one handed, without taking the pack off.
Credit: Lyra Pierotti
Ortovox introduced an interesting take on features for ski mountaineering with their Peak Light 32. Although it ultimately wasn’t a competitive pack in our review, it did fit its purposes very well with durable materials, a front access zipper, and an extra ice axe holster on the front of the shoulder strap.
Finding the ideal mountaineering backpack for your needs is a complex calculation of utility, durability, and comfort. Our testing metrics attempt to weigh several of the most important qualities of a mountaineering pack. We spent months comparing them, side-by-side, as objectively as possible. We hope that the descriptions of our experiences in the field help you to zero in on the pack of your dreams.
Keep in mind that our top-scoring packs may not suit your needs perfectly. Be sure to check out packs that score the highest in the metrics you care about the most. We have also included a wide variety of pack types in this review, but our metrics still reflect a solid performance for each pack in its specific niche of mountaineering. For example, we didn’t disadvantage expedition packs for being bigger. We assess relative sizes by looking at weight-to-volume ratios to better describe the quality of materials and thoughtfulness of design.
Mountaineering packs can take you all kinds of places. We hope you’ve been able to find the best one for your needs.
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