Free 2-Day Shipping on Orders Over $50* - Limited Time Only

Take 20% off one full-price item

Restrictions Apply >
Use Code: SPRING20


One pack that functions like three.

Go ahead, buy three different packs for different sections of your ascent―good luck carrying them all. If you'd rather not strap packs onto your packs, you can just bring the lightweight Mountain Hardwear South Col 70 Outdry Backpack, which is basically three packs in one. It's got plenty of space for a two-day winter mountaineering trip, and strips down to the basics to help on the summit push—you can pop off the top pocket, slide out the padded Hardwave suspension framesheet and aluminum stay, reduce the padded waist belt to a simple nylon webbing belt, and go fast 'n' light all the way to the top. 

When you're carrying a heavier load, leave the suspension in and walk cross-country in comfort. Along with rugged nylon fabrics, the South Col is kitted out with an OutDry waterproof membrane, which will keep all the gear in the main pocket dry as a bone, and features a front zip pocket that's easily accessible and maintains its volume, even if the bag is stuffed full. There are tons of lash points and straps for carrying skis, ice axes, and poles, an easy-access crampon stash pocket, and a top skirt that extends to give you an extra 300 cubic inches of space. Never bring two packs again.

  • Removable Alpine HardWave suspension, aluminum stay, padded waistbelt, and top pocket
  • Small/Medium fits torsos from 16-19 inches
  • Carries up to 60lbs
  • Top access
  • Durablie nylon fabrics with OutDry waterproof membrane
  • Front gear pocket and easy-access crampon pocket
  • Ski, ice axe, and pole carry
  • Compression straps

Share your thoughts

What do you think of the

Mountain Hardwear South Col 70 OutDry Backpack - 3975-4275cu in

? Share a...

Write a review

No file chosen

Rather attach a photo from another website?

Rather attach a photo from your computer?

    Add a:
  • Share a photo
  • Share a video


Only jpg, jpeg, png, gif or bmp files please.

Submit Cancel
Now review from the App. Download

Here's what others have to say...

Unanswered Question

I read that the pack does not have any hydration options built in. Is there anywhere I can keep a bottle or bladder in the pack easily accessible without taking the pack off?

Is there an older version of this pack which is NOT made with OutDry technology? Do all South Col 70 packs made with OutDry have an OutDry label on them?

Responded on

Answering my own question here after doing more research. Yes, there is an older version of the South Col 70 which does not have the OutDry technology.

4 5

Rookie at the Mountain Hardwear factory!

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

We were about to return this pack after my wife kept complaining about the discomfort when she wore it, fortunately I came here to see that it was just the metal wire had been installed the wrong way! Ha! Easiest problem solving ever. And it looks like there's a few other people with this problem...

Anyhow we haven't put this baby through the wringer yet but from what other people have said this is pretty much the next best thing to one of those Cilo custom packs... For half the price!

Question on fitting the South Col or BMG...

Question on fitting the South Col or BMG 105 OutDry backpacks: One important aspect of fitting a new backpack is to make sure the stays conform with the lumbar region of the hiker so that the load will be transferred to his/her hips, not the shoulders. The photo below shows a side view of the stays (actually one continuous metal stay bent into a U) of my new South Col OutDry backpack right out of the box. The plastic sheet (visible near the top) goes between the metal rod and the hikers back. The hiker would be on the right. Also in this photo is my template stay that has been bent to shape my lumbar region. Note that the curvatures are opposite. My initial thought is: Has someone at Mountain Hardwear assembled these stays backwards? The BMG 105 OutDry backpack stay came with the same orientation as the South Col. This is easy to correct by unzipping the Velcro strips holding it in place and flipping the stay around before adjusting (bending) it to fit. However, if I attempted to use either of these packs as they were delivered from, the bottom of the U-shaped stay would dig into the top of my lower lumbar, sacrum and coccyx and make for a very painful hike or climb. Am I overlooking something here? Thank you.

Question on fitting the South Col or BMG...
Responded on

I got the bag and was wondering about the same thing actually.

Best Answer Responded on

Hayes and Ven,

You are definitely not overlooking anything and your assessments are spot on. From the picture that Hayes included in the question, it is evident that the pack shipped with the aluminum stay reversed. The lower section of the aluminum stay needs to follow the lumbar curvature of the wearer, as with the template stay that Hayes also pictures.

It is an easy correction to make, but our sincere apologies for this shipping oversight from our Mountain Hardwear factory. The rectification is to un-hook the lumbar section, slide the stay out of the hipbelt, slide the stay out of the backpanel (easiest to also remove the plastic framesheet) flip the stay around and re-assemble.

Also remember that part of beauty of this pack is its flexible design, which allows removing pack components (i.e. swap the padded hipbelt for the included webbing belt and/or remove the top pocket, frame stay and/or framesheet when climbing with lighter loads). The minimum weight for this pack is approximately two and a half pounds with these components removed and the hipbelt swapped.

Alex @ Mountain Hardwear

Responded on

Mine was backwards too. I have been in an alot of pain my last few trips with it and it just thought it was something I had to deal with. Thank you for the feedback on switching the stays around.

Responded on

I have a question for Mountain Hardware >the photo above showing the U-stay,is it in the correct, or incorrect position.
My Pack arrived with the U-stay pointing inwards toward my back
I measured my spine/back and I come in at 21 inches, however the pack seems to ride low on my back ,rubbing the top of my Butt.
MY U-stay came pointing inwards unlike the photo which seems to be pointing outward, as you can discern from my comment I'm quite confused by the photo and the pack.
I have not trail tested the pack yet, perhaps it just a situation of me getting used to the new pack.[ Yes,I have adjusted the straps]
So ...should the U-stay be pointing inward's toward my back ,or outwards .......
Thank you for your response.

Responded on

Hi Stan,
The "copper"-looking stay that comes with the backpack (it actually anodized aluminum) in the above photo is installed backwards. Mountain Hardwear only shipped a few batches of the incorrectly assembled SouthCol and BMG backpacks and, once they became aware of the problem, quickly corrected it in all future shipments.
First, check to make sure your backpack is assembled correctly (the reverse of what is showed in this photo). If it isn't correct, you can easily take it out and reverse it. The next step is to adjust the stay if necessary. This is much easier in this new version of the SouthCol because you can take the U-shaped stay completely out of the frame. Before bending it, I suggest viewing some of the youtube videos on how to adjust a backpack stay (e.g. the HPG Ute Internal Frame Backpack Adjustment video]. Then bend the U-shaped stay to fit the lumbar region of your back. What I did was to first purchase from a hardware store a 1/8" x 1/2" flat aluminum piece 3 feet long and shortened the length to 26 inches. I practiced bending it to fit my back before adjusting the actual stay. This inexpensive aluminum rod is now a template for the stays of my backpacks. That is the piece of aluminum you see to the right in the photo above. If you have any additional questions, do not hesitate to ask. Good luck and good climbing! Hayes

5 5


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

One way to answer this question is to do an "OOPS, I FELL IN THE CREEK" TEST. To simulate this dunking, I filled a laundry tub with six inches of water and placed a 25 pound lead brick in the pack and lowered it into the water. Parts of the pack were submerged to about 8 to 12 inches well above the bottom seams. Each pack was left partially submerged in water for 10 minutes and then removed.
a. Results of dunking my older, and well-used Mountain Hardwear South Col backpack (my favorite backpack, but not OutDry): After 10 minutes of partial submersion, this older South Col backpack had a pool of water inside. It took up 700 gm of water, enough to fill a 1 liter Nalgene water bottle 2/3 full.
b. Results of dunking the new OutDry backpacks: There was no visible pool of water inside the South Col OutDry backpack but it felt damp. To measure how much moisture seeped in, several sheets of dry paper towels were weighed and then used to swab the inside of the pack. The paper towels gained about 4 gm, so they had absorbed 4 ml of water. The BMG 105 OutDry backpack is much larger and thus had much more fabric and seams exposed to the dunking. Again no pool of water accumulated in the new BMG 105 OutDry pack. The paper towels used to wipe the inside of this big pack gained 20 g. Conclusion: The OutDry construction is a big improvement, reducing the water uptake by over a factor of 100 in this test (700 ml/4 ml= 175). This is not a perfect test because I do not have an older South Col in new condition to compare with the new OutDry version, although I have treated my old South Col with waterproofing sprays in the past. No backpack is completely waterproof under all weather and exposure conditions. I plan to continue packing my sleeping bag and spare clothing in dry bags.
I give the OutDry fabric/treatment 5 stars. I am impressed with the new features on both backpacks but reserve a rating of the packs until I have had more experience with them.

Responded on

Since my original post, I have run three additional tests of waterproofness on two OutDry backpacks. Calling the above OOPS, I FELL IN THE CREEK the TEST #1, here are the additional three tests and results:
Test #2. I GOT CAUGHT IN A THUNDER STORM TEST. The set up: The backpack was then placed upright on a plastic box in a home shower and four rain gauges were placed around the corners of the pack. The RAIN was simulated by turning the cold water (18 C). This shower delivered three inches of water in each rain gauge in 5 to 10 minutes after which time the water was shut off. This simulates a severe thunderstorm which is moving rapidly (e.g. high winds), drenching a hiker and moving on. RESULTS: Upon opening the two new OutDry South Col 70 or BMG 105 backpacks, no pools or droplets of water were observed inside and they did not feel damp. To test for moisture inside, sheets of dry paper towels were weighed using a hanging spring scale. The sheets were then used to swab the inside of the backpack and the plastic wastepaper basket inside the pack, and then weighed again. No weight gain was registered. Conclusion: OutDry kept out all the moisture from the main backpack . The inside of the lid (map compartment, which is not OutDry) did feel damp and swabbing with paper towels indicated some moisture (5 to 10 gm) had seeped into the lids of both backpacks. In contrast, my old South Col had small pools of water inside all compartments of the pack (main, front inside pocket, and two inside the lid compartments, est. total water 100 gm).

Responded on

Test No. 3 THE DRYSUIT TEST. The set up: taken from a YouTube video "DOGTV Drysuit Leak Test/do-it-yourself By Bob Stinton. The backpack was inverted and placed on a slanted table and 3 gallons of water were poured into the top. RESULTS: Most areas of the OutDry membrane was tight (no leaks) but there were some spots near the bottom of the backpack where water got through to the outside of the inverted pack.
Test No. 4 THE SOAP BUBBLE TEST. The set up: Similar to leak testing bicycle inner tubes. The inverted pack was placed on a slanted table; an air hose from a Shop-Vac was inserted into the top of the backpack loosely. A soap solution (1 part dishwashing detergent and 4 parts water) was applied to sections of the smooth surface with a paintbrush, and any bubbles were noted. Result: there were a few isolated spots where bubbles formed, probably representing pin holes, but most (99%) of the surface was clear of any leaks.
CONCLUSION: The results of the RAIN TEST show that the new OutDry material protects the contents of a backpack in a rainstorm. The remaining three tests set a higher standard because it is well known that water penetration increases with pressure. These three tests show that although the OutDry backpacks are a huge improvement, they are not quite perfect. There are some small leaks (pin holes?) present in the two packs tested. The folks at Mountain Hardwear have been very receptive to new information and they are working on eliminating these small defects. My conclusion: The OutDry deserves 5 stars.

I like the weight, size and the fact that...

I like the weight, size and the fact that it is waterproof but no place for a water bladder? What are the options for hauling and accessing water on this bag? From the pictures, it doesn't look like there are easily accessible side pockets but it is hard to tell. Thanks.

Responded on


A reservoir/bladder may be carried in the floating top pocket or in the front zippered pocket (though the latter is not ideal for weight distribution). Water bottles may also be carried in the top pocket, front zippered pocket and/or front crampon stash pocket (presuming you're not carrying crampons).

This is a mountaineering pack so Nalgene water bottles are usually carried inside the pack since they tend to freeze at higher elevations if they are outside the pack. Even though it's a mountaineering pack, the reasons you noted (weight, size and the fact that it's waterproof) make it a great backpacking pack as well!

Alex @ Mountain Hardwear

5 5

Awesome pack!

  • Familiarity: I've used it several times

This is an awesome multi-purpose pack. It's designed for multi-day alpine climbing trips. It would make an awesome pack for Mt. Rainier or Aconcogua. It would also be a good all around backpacking pack. The OutDry membrane keeps everything in the pack nice and dry. Great for the Pac NW and the AT. Really comfortable with around 45-50 lbs. Super durable too. Just a really good pack.