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Osprey Packs
Mutant 52L Backpack

5 out of 5 stars
4 Reviews
Color:Tungsten Grey


Size Chart


Mutant 52L Backpack

For big objectives and epic missions, the Mutant 52L Backpack is the pack to take along with you when you're planning on moving light and fast. Osprey slimmed down this pack so it only has the necessary bells and whistles to accommodate the tools you need to get the job done while playing in the high mountains. The large volume provides enough space so you're able to hike all your gear in to set up basecamp, and still sneak in a couple extra luxuries of home. Gear loops on the removable waist belt add access to extra gear when you're on the move, and a three-point haul attachment evenly distributes the weight of the pack so it can be stored at an anchor and hauled up a pitch when the climbing gets technical. Additional helmet and ice tool carry means that you can store your gear safely and securely on the way back to the car.


  • A backpack for light and fast missions that could span multiple days
  • 52 liter capacity carries the necessities and extras so you're prepared
  • A-frame ski carry system hauls skis securely while ski mountaineering
  • 3-point haul attachments distribute weight evenly for hauling up climbs
  • Gear loops on waist belt allow for additional gear storage and access
  • Ice tool carry points safely haul ice tools on the approach
  • Helmet carry attachment stows helmet during the hike back to the car
  • Removable waist belt shaves weight when counting grams
  • Item #OSP00BB
[main, accent] 210D nylon, [bottom] 420D nylon
[small/medium] 50L (3051cu in), [medium/large] 52L (3173cu in)
removable atilon sheet lamination, HDPE top stay
Shoulder Straps
laminated EVA
Waist Belt
Hydration Compatible
2 zippered lid
Gear Loops
1 front panel daisy chain, 2 waist belt gear loops
Helmet Carry
Ice Axe Carry
Weight Capacity
29 x 13 x 13in
Claimed Weight
[small/medium] 3lb 3.8oz, [medium/large] 3lb 6.6oz
Manufacturer Warranty

Overall Rating

5 based on 4 ratings

Review Summary

1 Stars - 0 reviews
2 Stars - 0 reviews
3 Stars - 0 reviews
4 Stars - 0 reviews
5 Stars - 4 reviews

Fits True To Size

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5 out of 5 stars

December 3, 2023

Outstanding alpine pack

I've used it several times
Size Bought:
5' 10"

I took this pack on a 3-day (guided) climb of Mount Baker. Most guide services suggest an obscenely large pack size for such a short trip (e.g. 65-75 L). However, by choosing gear wisely and packing carefully (watch videos on how to pack a climbing pack) I was easily able to fit all my clothing, gear, shared gear, and food for this trip, with even a bit of room to spare. A larger pack would have been not only overkill, but probably induced me to bring more useless stuff! The design is very thoughtful, from the removable top, to the mesh helmet net. The side pockets are sized to fit wands or snow pickets, and _not_ water bottles. There are load-tightening straps, and places to secure your ice axe or ice tools, as well as crampons, but that's it -- and that's a good thing. This pack helps you minimize "danglies" while still offering essential tiedown points. Overall, I gladly recommend this for 2-4 day alpine climbing/touring/skiing trips in Summer; perhaps 1-3 days in Winter.

James B
5 out of 5 stars

November 21, 2023

Excellent winter SAR pack

I've used it several times
Size Bought:
6' 2"

Have used this pack a few times for fun but recently used it for an overnight SAR training mission here in CO. Wore it for around 12 straight hours and 10 miles of hiking, lots of vert while carrying a litter etc with a 35lb winter loadout, full volume. Back does get sweaty af even at 25 degrees at night with just a base layer but I somewhat expected that given the design. Padding is very minimal but somehow handles 35 lbs of gear very comfortably and could probably go up to 50 which is stellar for this light of a pack. Load is very stable and moves with my body extremely well. Will test out the ski and ice axe carry soon. Material seems durable. Simple pack but has everything I’ve needed so far. Helmet “net” is perfect. I have the smaller Mutant as well (also great) but would really like one around 75 liters for carrying additional winter and tech gear. Insanely good pack for the money.

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J M49
5 out of 5 stars

June 7, 2021

Love it for cragging

I've put it through the wringer
Size Bought:
6' 1"

I don?t alpine climb but I bought this pack because of all the features and they all actually held up. I can throw my whole rack in my bag with a 70m rope on top and it comfortable with all the adjustments to the pack and I only have the 38L. With sport climbing I use the ice axe straps to hold my extendable stick clip. Another bonus with it being a alpine pack it?s pretty water proof. I got stuck in a couple of thunderstorms over a weekend and everything was soaked except what was in my pack. My rope and gear were dry inside. My only request would be for the rain top to be removable for lighter treks and easier access. Other than that 10/10 would recommend for and climber alpine or not

Phillip T
5 out of 5 stars

January 16, 2021

Excellent mid-range mountain pack

I've used it several times
Size Bought:
5' 11"

I bought this pack AFTER I'd purchased its smaller sibling the Mutant 38. I was so impressed by how focused the pack was on durability and purpose. The shoulder straps feel great once the pack has weight in it, the hip belt with loops is really useful, especially if you're moving with a lot of gear or need to hook a water bottle somewhere. I like that the 52 has "picket pockets" that you can use to hold anything from tent poles to pickets. I initially bought the 38 for shorter trips into the rockies with a day's worth of climbing gear and supplies but as time went by my objective became more time-intensive so I bought the 52 to carry 3 days of food and supplies along with my trad kit. I do appreciate that you can strip the pack down, although if you're going up on a rope I don't think I'd strip the pack down and use it on climbing routes unless you're moving for days on end, such as completing a cirque or traversing a range. If you're on a single day trad route, I'd bring a much smaller pack like a cotopaxi luzon that would double as a stuff sack. I like that the pack keeps the weight centered, how narrow it is at your hips to accommodate a harness, and how durable it is. I plan on using the 38 in the Rockies but the 52 is part of my kit for a longer trip in Gates of the Arctic that will keep me away from our base camp for 3-4 days at a time. My only suggestion is to include shock cord or something elastic on the front of the pack. I see a lot of people talk about avy gear and it makes sense to have a pack that lets you carry a shovel, but this is a climbing and mountaineering pack and something to secure crampons with would be a way better addition than a place for a shovel. Just my thoughts.

Nathan M