SmartWool Mountaineering Sock

Priced: $14.50 - $25.95 Rated:   - 4 stars out of 5 by 106 reviews.
SmartWool Mountaineering Sock
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Color: Natrl / Gray
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SmartWool Mountaineering Sock -

The SmartWool PhD Mountaineering Socks fit smoothly, comfortably, and easily into your low-volume mountaineering or hiking boots for incredible comfort when you bag peaks and tackle rough terrain. These heavyweight socks feature temperature-regulating merino wool fabric, strategically placed mesh ventilation zones, and a heavy-duty heel and toe.


  • Extra-thick 3 x 1 knit with mid-calf design provides extra protection and a snug fit
  • 4 Degree Elite fit system uses two elastics for greater stretch and recovery to keep the sock in place
  • Rib-knit welt top and Lycra spandex braces above the ankle help keep socks up for a wrinkle-free fit and less chance of blisters
  • Flat-knit side panel reduces compression for a better fit and max ventilation


  • At least 75% merino wool, remainder nylon and elastic
  • Merino wool's antimicrobial qualities inhibit feet funk while elastane fabric offers comfortable stretch
  • Wool-on-wool construction in the heel maximizes the lifespan of the sock
  • Natural merino wool features long, silky fibers for extra warmth and comfort without wool's itchiness
  • Merino wool, nylon, and elastane fabric blend wicks moisture away from your feet for increased comfort, dries quickly, and breathes exceptionally well while you hike


  • High-density sole padding cushions against shock, blisters and abrasions; high-density padded insteps and shins protects against lace pressure

Support and Cushioning:

  • Heavy cushion heel and toe ensure maximum comfort and protection in the highest impact areas of the socks
  • High Density Footbed provides extra cushioning for improved shock absorption and durability
  • Arch area is knit with elastic for increased support and comfort


  • Flat-knit side panels add breathability and ventilation to keep feet comfortable
  • Strategically placed mesh ventilation zones supply ventilation for temperature and moisture management

Weather and Wind:

  • Flat-knit, durable toe seams for high-burst strength


  • ReliaWool technology in high-impact areas provides longer lasting protection to keep your feet comfortable
  • Flat knit foot and leg with heavy duty yarns for maximum comfort and protection in low-volume mountaineering boots


  • Made in United States of America USA


  • Smartwool fibers regulate body temperature to keep you warm in the winter and cool in the summer
  • 2x rib top with elastic holds the sock in place
  • Discount will be applied when you check out. Offer not valid for sale-price items ending in $._3 or $._9
  • Heavyweight
  • US shipments only
  • Smartwool Merino fibers are naturally odor free
Sierra Trading Post
These SmartWool socks are made to put the comfort back into heavyweight boots. This is SmartWool's heaviest sock ideal for stiff mountaineering boots or frigid conditions. Features extra-heavyweight insulation and a higher cut for wearing with taller boots.

Eastern Mountain Sports (EMS)
The SmartWool Mountaineer Socks are made of fast-wicking, non-itching merino wool. Extra warm for winter use. Recommended for the backcountry.

Fiber Content: 82% wool, 15% nylon, 3% elastic.
Country of Origin: Imported

Mountain Gear
The SmartWool Mountaineer was made with greater cushioning for longer periods of trekking up and over mountains, and increased support over the ankle to prevent blisters in stiff mountaineering boots.


High-performance SmartWool Mountaineer socks are designed for maximum comfort, protection and warmth over extended periods.

Made in USA.

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Average Price History: Price History
Review RatingNumber of Reviews
Country of Origin:USA
Fabric:80% merino wool/19% nylon/1% elastic
Material:83% Merino Wool. 16% Nylon. 1% Elastic
Overall Height:14in
Sock cushioning:Heavy cushioning
Sock height:Crew
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SmartWool Mountaineering Sock Reviews:

Positive Reviews:

My favorite socks by a wide margin

I work in forestry restoration, and I wear these socks with my steel-toe boots that are no longer waterproof. Even after hours in the snow when I know my feet are soaked, these socks are still cushy and keep my feet reasonably warm (they even *feel* dry!). For example, earlier today: my feet didn't get cold until the very end of the day, but seriously... they were sopping wet ALL day from the holes in my boots. In fact, my pants had gotten wet and were frozen solid to my boots, but my feet never went numb and stayed surprisingly comfortable. I really don't believe there is another sock out there that can do that. If I was wearing cotton socks today I would have been miserable within the first hour (I know this because I used to wear cotton socks... never again!).

They're the most expensive socks I own, but they're by far the most comfortable and functional socks I own. I will be buying more of these, just spread out over a few paychecks :-)
ChiTownHiker at REI on 01/01/2012

Truly excellent socks

I've been able to use these socks several times on day hikes ranging from easy to moderate and they have been so comfortable on every outing. I have noticed to make comforts about them. One the are very cushioning, my feet always feel padded and comfortable all day. The second, they are always the perfect temperature. When I'm hiking they never feel excessively hot and when I stop they are pleasantly warm. I've always had problems keeping my feet at a nice temperature, either my feet are blaring hot and sweaty or freezing cold, and these have completely fixed the problem. They only complaint is the price, I'm thinking of trying the REI equivalent for a small price savings but I did notice when I compared the two brands side by side by flipping then inside out that the smartwool brand does have substantially more cushioning and threads, so I imagine you get what you pay for.
Project48 at REI on 04/04/2013

Must have Summit Sock!

This sock coupled with a good liner (I tend to size my liners one size smaller so they don't bunch) is the perfect combination for a summit climb. Wore these on Mt Adams this past summer and my feet stayed perfectly warm in my old set of Raichle boots (didn't have enough to break in my new La Sportiva's).
This is warm sock, and does a good job wicking away the moisture. Also they are bulky. So if you hike the year round in a medium to heavy hiking/backpacking sock, this sock is one-up from that. Don't try to cram you foot into a snug boot (I buy mine 1/2 size larger for this reason), it will defeat the purpose and keep your feet cold.
They are spendy, but this will be the one and only pair of winter/mountaineering socks you'll ever need to own.
Hike on!
Papa Packer at REI on 11/11/2013


These socks have literally improved my quality of life. I do a lot of maintenance/mechanical work outside in Chicago winters and these socks have made every day just so much better.

I bought them because they seemed like the warmest in the line, and they are great.

My feet were toasty and comfortable (nicely padded on bottom, heel, and toe)and not once were they sweaty or itchy (problem I had with other socks). True to the other reviews, they did not stink after wearing them all day.

These might be overkill for lighter use, but if you know that you will be very cold for any extended period of time I highly recommend investing in a pair. That being said, I am wearing them right now, inside the warm house, and they aren't uncomfortable at all.
ramseym at REI on 02/02/2010

So warm I forgot I had feet

Great product! In terms of warmth, they hold heat all day. I spent a day on the slopes in Colorado with them and never had any issue. Usually, my feet get cold a few hours into any outdoor activity in the the winter, but with these I never noticed any creeping coldness.

However, with the good comes the bad. The reason I gave them 4 stars was because they fit a bit large. While they are super warm the elastic band at the top that fits around the calf is the only part of the sock that seems to stay formed around your leg. Everything else fits loosely.

Although there is this issue, the primary reason for purchasing this sock is warmth and under that criteria it passes. I would recommend this sock.
Dreaming of the AT at REI on 01/01/2014

Excellent, comfortable socks!

As Smartwool states on their packaging, these are ‘seriously comfortable socks’. Made from 80% wool, 19% nylon, and 1% elastic, the Smartwool Merino fibers provide incredible efficiency in wicking away sweat and water, as well as maintaing an uncanny ability to control odor . The socks are versatile in providing superior regulation of body temperature by keeping feet plenty warm in the winter, and they were clockwork while we trudged through a significant amount of snow in the Colorado front range. These socks were built with extra heavy cushioning in mind, a feature that is a must when challenging yourself on a winter mountaineering ascent Color and size options are abundant, and for [$]retail, they may seem pricey but your feet will be thankful that they were wrapped in these babies.
JPFreek at REI on 09/09/2007

Very good socks for hiking

I bought this socks for hard tracking with backpack over 20 kg and radial excursions to peaks. It have been tested in the winter outdoor event where we pass from 1200 up to 3095 meters, temperature was from -3 to -12 celcius degree. And it was snow up to 60 cm. I have a little problems with cold legs only at night when we stay for two hours while waitings for ropes mounted. All other time my feets was dry and warm. Finally it is only socks I have no any blisters with my Salewa Bison GTX trecking boots! I planned to use them one day only but feel very comforatable for more than 3 days. Now I planning to buy two additional pairs for everyday outdoor usage.
HuronMaramba at REI on 01/01/2012

Toasty Warm, Wicks good, All day comfort

Haven't used this pair yet, but I have other Smartwool socks and they wick moisture amazingly. I slipped and stepped both feet in a stream that went over the tops of my Gortex hiking shoes, and the Smartwool socks still kept my feet warm, even before I stopped to take off my shoes and wring loads of water out of my socks. I put them back on and kept going without discomfort. The mountaineering socks are the thickest they make and should be toasty warm, but they aren't much use around New Jersey. You have to got to find some real cold before you want to wear these. I would go thinner if you aren't headed north for the winter or up to high altitudes.
Jay-man at Eastern Mountain Sports (EMS) on 12/12/2011

Warm and comfy

Got these based on good reviews here, wasn't disappointed. I've had other Smartwool socks that I've liked a lot (and some older ones that were only ok), and these are in the former camp.
I've used them several times for ice climbing, and they are more comfortable and warmer than the 2 pair (liner and ski socks) system I had used prior.
My feet are size 9, and I got the M (7-9) and they fit well, L would have been WAY too big on me. If in doubt, size down a size, they are socks, they will stretch if need be.
These are fairly thick and bulky, so be sure there is room in whatever footwear you intend to use them with.
Murphy'sLaw at Eastern Mountain Sports (EMS) on 02/02/2009

Great Hot or Cold...

I have worn these socks on a daily basis in Danner
work boots summer and winter, and inside a pair of White's Pac-Boots in extreme cold conditions for the last 5 years while working in the forest. I wear a fresh pair each day, and with weekly washing they have held up great.I keep about 6 pair on hand, and I have only had to replace them about every 18 months on average.Drying them in the dryer takes a toll on the elastic in the upper part of the socks over time.They are a lofty sock and wick moisture away from your skin in hot or cold to keep your feet comfortable, and
give additional cushioning to your feet.
4SCruiser at REI on 08/08/2009

Negative Reviews:

These are cool socks warm and go right under the knee.
I would choose the Smartwool heavyweight socks though they are warmer then these . For 25.00 they could have added more beef to be honest the wool is on spots not all over the foot .

mario sarrica at on 12/02/2013

Warm but droopy!

The Mountaineer is warm, soft and a cushioned sock, but the lack of good elastic makes it a bit droopy. I had to keep pulling them up!
Jay at Mountain Gear on 03/03/2008

Neutral Reviews:

Disappointing Warmth

I got these to keep my feet warm when unexpected 20 to 30 degree weather came in while using a +25 sleeping bag.

Wearing two other pairs of socks underneath them, my toes still got cold. At 27-30 it was ok, but from 26 and under toes were cold in the morning.

They're clearly nice socks otherwise and probably good for intended use, however in my situation they just didn't perform as I would have liked.
royce44 at REI on 12/12/2013