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Osprey Mutant 38 Litre Climbing / Mountaineering Backpack


Sale price $133.00 Regular price $153.00

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Designed by guides and athletes, the Osprey Mutant 38 Litre Climbing / Mountaineering Backpack fits perfectly between its bigger and smaller siblings; great for long days in the mountains that don't require setting up basecamp but might require a ledge-bound shiver-bivy. The backpanel sheds snow and easy-to-use ice tool attachment and glove-friendly buckles mean less time fiddling with your pack. With a hipbelt that includes gear loops and stashes behind the pack to provide access to your harness when you need it, plus integrated helmet and rope carry, the Mutant 38 is a nimble and capable alpine machine that fits better and feels more comfortable than what you’re used to. Whether you're enjoying a North Cascade's classic or getting showered by spindrift in the Canadian Rockies, the Mutant 38 can do everything you need except belay you on the next pitch. 


  • Built to be lightweight and reliable with alpine-specific features such as dual ToolLocks with bungee tie-offs, helmet carry, strippable features, rope carry and a narrow profile for efficiency in the mountains.Quick-release upper side compression
  • Removable top lid, removable suspension (framesheet on 22L, framesheet and/or dual stays on 38L/52L), allow the user to trim weight.
  • Osprey's superior fit makes for efficient and ultimately safer movement in the mountains so that you're never thinking about your pack during runout cruxes through rotten rock or thin ice."
  • Snowshed fabric backpanel
  • Dual ToolLocks with bungee tie-offs
  • Front panel daisy chain for additional gear attachment
  • Three-point haul system
  • Internal hydration sleeve
  • Glove-friendly buckles
  • Rope attachment and internal compression
  • Removable top lid with integraged FlapJacket for lidless use
  • Top or front of pack helmet carry
  • Reinforced A-frame ski carry
  • Quick release upper side compression straps
  • Lower side compression straps
  • Dual hipbelt gear loops and ice gear carry attachment
  • Reverse-wrap hipbelt

Key Fabrics used:

  • Main: 210D High Tenacity Nylon
  • Accent: 210D Nylon Honey Comb Contrast Thread
  • Bottom: 420HD Nylon Packcloth


Load Range

5 - 18 kg

Volumes and Weights

US and International weight and volume specifications

Size liter kg.
S/M 36 1.2
M/L 38 1.3


Dimensions are shown as length (height) x width x depth

Size M/L
IN: 28.7 x 12.6 x 11.8
CM: 73 x 32 x 30

Osprey Mutant 38 - Outdoor Gear Lab Editor's Choice Award
For the second year in a row, the Osprey Mutant is our Editor's Choice Award winner. The Mutant is a feat of pack design and engineering. It has an impressive ability to haul heavy loads with (relative) ease, then mutate into a summit machine. You can strip it down to the essentials for a lightweight summit push while retaining the features you need to keep your technical equipment secure and accessible on the climb. The pack is only 38 liters, but we can pack it with equipment for trips that usually require a 50-liter pack. We attribute this to a thoughtful suite of features and a tapered design that accommodates lightweight but bulky items like jackets or tents at the top of the pack. If your climbing kit is lightweight, we think you'll be able to stretch the boundaries of the Mutant, allowing it to replace at least a couple of packs in your quiver.Outdoor Gear Lab, 2018.

Sizing and Fitting of your Osprey Pack

Fit is the key to pack performance. Take the time to get it right. Most Osprey packs are available in multiple sizes to fit a range of torso lengths. To find your torso length, have a friend measure your back along the spine (as shown in the picture below) from the level of your iliac crest (the top of your hipbones) to your C7 (the knobby bone at the base of your neck).
Use the table below to determine your pack size.
Mutant 38 Litre Backpack Small/Medium Medium/Large
Back Length 15-19"/38-48cm 18-22"/46-56cm