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The pack for big loads, big miles, and big terrain.

If your backpacking trips require you to measure the time in weeks and count the miles in the hundreds, it's probably time to invest in the Arc'teryx Altra 85 Backpack. The C² Suspension System reduces fatigue and load movement by keeping the pack close to your body, which allows you to move more efficiently and safely on technical terrain with a heavy load. The top lid can be extended to accommodate extra-large loads, and the burly silicone-coated nylon fabrics provide unmatched durability.

  • C²Suspension System utilizes high-density foams laminated to a quick-dry back panel—this system keeps the pack close to your body for greater efficiency and reduced load movement
  • Dual 6005 T-6 extruded aluminum stays provide structure and support for heavy expedition-style loads
  • Gridlock shoulder straps and waist-belt adjust in height and width for a fully personalized fit
  • Straps feature Hypercell foam and a Spacermesh lining for improved stability and ventilation
  • Rotating Load Transfer Disc effectively transfers weight to the hips, allowing you to comfortably shoulder heavy loads
  • Top access allows for organized packing while a large U-shaped zipper provides easy access to the main compartment
  • Extendable top lid and extension collar create additional space for large loads
  • Burly nylon ripstop fabrics have a silicone coating that's resistant to water, snow, and dirt
  • Hydration sleeve can be accessed externally for easy refills (reservoir not included)
  • Large front kangaroo pocket provides quick access to a rain jacket or puffy
  • Wingman easy-access pockets allow you to grab gear with one hand while you're on the move
  • Mesh waist-belt pockets keep trail essentials close at hand
  • P'ax ice tool carry system keeps ice axes securely stowed

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Here's what others have to say...



  • Familiarity:I've put it through the wringer

After trying several large capacity backpacks, I have finally found one that works! I purchased this pack to carry large heavy loads (see family gear), and it has exceeded my expectations. The moving hip belt freaked me out a bit at first, but I have had no hot spots on my hips after long, heavy days. The construction is great and has held up to several backcountry trips. Although a bit pricy, this pack it well worth it!


Best Multiday Pack On the Market

  • Familiarity:I've used it several times

This pack is by far the best large volume multi-day pack Ive ever had. First trip with it was a 2 night run into Yosemite - with camera gear (body and 2 lenses), tripod, and other gear it was loaded to about 60 lbs and the hike I did was 7 miles each way with about 2500ft of vertical gain going in. I never once had shoulder fatigue OR hip fatigue. The weight rested perfect on my hips and when the pack is cinched down it is totally stable. The suspension system ROCKS and the ability to dial in the fit is superb. The top lid has TONS of space as well and organization is clean and easy, enough pocketing to be organized but still keeping a clean and streamlined profile. 3 different people stopped me to ask about the pack. I cant wait to take this beauty out for 5-7 days. The extra money spent for a pack of this quality is totally worth it for enthusiasts like me. Pay the money and get the right gear and then you can simply enjoy the trail instead of massaging your neck and downing Advil at camp!


good all around

  • Familiarity:I've used it several times

have used pack a good bit in CO mountains and for 1 week in winter on Rainier. It's quite large, but I did have difficulty placing a large winter sleeping bag in the bottom sideways even with a compression stuff sack. It stood up to snow without any difficulty, but in driving rain, the top pocket contents became moist though not totally wet. I would describe it overall as very hardy and able to take a good bit of abuse. Interestingly the back cushion on one side, which is non-load bearing, ripped off the back panel when I was adjusting the shoulder strap height. This was odd given arcteryx's usual quality, but was easily solved with some glue. The shoulder adjustment mechanism is really terrific and the rotating hip belt was way more comfortable than the Mountain Hardwear BMG that I had used prior.

where will i put the ice axe in this pack?


The pick of the axe will slide into the side of the bottom 'kangaroo' pocket and the shaft is simply held in place by the compression straps.

Unanswered Question

This isn't a women's specific pack. Any complaints from women about the fit?


As good as they all say it is!

  • Familiarity:I've used it once or twice and have initial impressions

I have not had a chance to take this particular pack out but so far I am very pleased with it.

Very toughly constructed. I feel that this pack can take everything I can throw at it and then some. Plenty of room for what I want to stuff in it.

The rotating hip belt feels great. It will be a great asset if used while scrambling around some rough patches.


Wow...I'm impressed. Amazing!

  • Familiarity:I've used it once or twice and have initial impressions

Okay, You'll see below I was skeptical about the Rotating Load Transfer Disc but it turns out this the KEY to why this pack is so amazing. Took this pack up Mt. Shasta with about 40+ pounds of gear. Somehow once you get the pack on, the hip belt makes the weight seem to disappear. I felt nimble and energetic where usually with this much weight I feel sore and stiff after one day. Highly recommend this new system.

I wanted all the little gizmos that other bird-named packs have, but my SMG guides on Shasta convinced me to just use the various loops to hold ice ax, poles, crampons, etc. I guess the elastic gizmos break and a simple strap is more versatile.

All in all this pack carried heavy weight with ease, gave me great mobility while climbing, had lots of convenient features like the U-shaped zipper to access everything and the kangaroo pocket to store extra layers, etc. and really seemed to hold more than the 85L.

Guess my only complaint is that the wing pockets on both sides of the hip belt are very tight to hold a 1L Nalgene type bottle. You have to work to get the zipper up or risk having the bottle fall out. Guide services don't like the bladders for high altitude/cold.

This is my new go-to backpack for heavy loads. Really is awesome.

I'm on the tall side and have about a 23...

I'm on the tall side and have about a 23 in torso. This is 1 inch more than the range recommended for the RT version of this pack. In the past I've had trouble fitting various packs comfortably. Can anyone comment on how well this specific pack fits for taller individuals?

Best Answer

I had the regular and had to upgrade to the tall because I was right on the line. The adjustability of the pack is quite good, but you do need to get the right size to start. The shoulder straps are easy to adjust both vertically and width-wise. Try it an see!

Just got this pack and it seems rock solid...

Just got this pack and it seems rock solid with great features. I'm worried though about the "Rotating Load Transfer Disc". If this thing breaks the hip belt has no real attachment to the pack, scary! I'm going up Aconcagua with this. Does anyone have guidance/advice? How long has this gizmo been around? I have lots of Arc'teryx gear and it's always bombproof but anything designed around thin plastic scares me.

Calif Adventure Gal, the Rotating Load Transfer Disc is a proven, reliable Arc'teryx technology that has been in the line for many years now.

I would recommend bringing the included tube of silicon lube on your journey. The system does require a small amount of lubrication periodically to avoid squeaking.

Fear not, the RLTD is robust and will serve you well!

Thanks Stephen for the assurance. I have to say the hip belt is incredibly comfortable. BTW, this pack did NOT come with the "included" tube of silicon lube. Will Arc'teryx ship me some? Is there a recommended kind/brand to use?

Best Answer

It's not really a tube.... more like a quarter sized ketchup packet. Took me a while to find mine in my pack when it first came.


The best on the market

  • Familiarity:I've put it through the wringer

There is no doubt.. This pack is amazing! I used it on a 10 night backpacking trip this winter in the Smoky Mountains averaging ~8 miles per day as well as many other trips and many of miles of training. For the 10 night trip, the pack started out at 55 lbs and felt great the entire trip. In training, I have filled the pack up 100+ lbs with both me and the pack feeling no soreness! I am 5'9" and 135 lbs and chose the short/regular size with a small hip belt. This pack really has no problems. It is huge, compresses extremely well, holds a 3L hydration pack easily, sheds water and snow, super hefty, simple, and comfortable. I am so glad I spent the extra money for a lifetime investment!

The best on the market
Best backpacking item I own!

Best backpacking item I own!

Heading out on the "under the rim trail" in Bryce Canyon UT.

Awesome picture Grant !!!

I selected this image to feature on the homepage in our Activity Feed! Congrats on being GOATWORTHY !!!


If you want it, This can pack it

  • Gender:Male
  • Familiarity:I've put it through the wringer

This is the best pack on the market for expedition backpacking. I used to hike with the bora, and the Altra is a fitting successor. I can use it for any trip from a few days to a few months. For the shorter trips I can pack the essentials and the party with room to spare! For the longer trips I can pack everything I need in a organized and simple manner. In comparison to other packs out there, I feel this bag keeps things simple and practical. The large outside pocket is a perfect compartment to utilize when some of your items get wet and you want to keep the rest dry. The pockets in the top of the pack are a great design as well. They have been built so your items do not dump out immediately upon opening them. The pack also has 3 large pouches that accommodate a hydration system or lager water bottles. The entire pack is accessible when fully packed, which makes dumping the entire contents of your pack in search for the granola bar a thing of the past. This is one pack I know I will still be using in ten years. If you can afford it, this is the top of the line for long term trips!

If you want it, This can pack it