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Reviews > Clothing > Base Layers and Undies > Mountain Khakis Bison Boxers and Briefs > Test Report by Robb Pratt

September 10, 2019



NAME: Robb Pratt
EMAIL: unicornv007 AT
AGE: 48
LOCATION: Canton, Michigan, USA
HEIGHT: 5' 10" (1.80 m)
WEIGHT: 165 lb (74.80 kg)

I backpacked sporadically growing up and rediscovered it back in 2011. Since then, I've taken several weekend trips a year. I also car camp with my family roughly a dozen nights a year when we use tents unless I can convince them I might snore and it would be better for all for me to use my hammock rig. I prefer a light pack (weight without food or water under 20 pounds / 9 kg). My backpacking stomping ground is northern Michigan that has small hills and I typically camp late spring, summer and early fall months.



Manufacturer: Mountain Khakis
Year of Manufacture: 2019
Manufacturer's Website:
MSRP: US$27.95
Measured Weight: 3.1 oz (91 g)
Other details: The Mountain Khakis Bison Boxer Briefs are lightweight and fast-drying underwear. They are made mostly of nylon (92%) and designed to provide unrestrictive movement and a comfortable "ride" with enough space in the front for "everything" to breathe. They also are listed as being antimicrobial for odor control to ensure freshness. Lastly, Mountain Khakis has added their own signature MK inseam action gussets and a brushed elastic waistband for extra comfort and to limit chaffing. They come in 5 different colors (I received the Black) as well as 5 different sizes (I received a large as my waist measured 35 inches (89 cm).

Package Front
Package Back


The package for a pair of underwear is about the size of a soft-cover book. It is clearly labeled and includes a sizing chart on it. It even has a small (buffalo-shaped) hole in the front that I can feel the material through before opening it. The packaging also (humorously) notes these are designed to be "Rocky Mountain Oyster Holders" along with the good stuff of antimicrobial for odor control, wicking, quick-dry, stretch, lightweight, breathable, brushed waistband for comfort, inseam action gusset and flatlock seams.


Opening the package up, I am very impressed with the material and the stitching. To the touch, it feels very soft and is quite stretchy. The seams are all very flat and do not have any obvious abrasive ends or spots - even at locations where multiple seams intersect. I also did not find any stray threads that needed to be clipped.

Inside Seam Intersection


After decades on this planet, I hope I know how to use underwear, but I still flipped through the package to pay attention to the cleaning instructions. I've never been afraid of the challenge of doing my own laundry. I actually handle all the laundry duties of my hiking cloths so I have only myself to blame if I accidentally turn a load pink or shrink up my favorite shirt. Either way, I admit to being puzzled by some of the symbols on the label. Much like every guy driving in a foreign land, I didn't consult my wife to ask for help with the directions. No, I went straight to the internet and looked up laundry tag symbols. Most of these are obvious and is exactly what I would normally do for cloths - wash in cold water, normal tumble dry and no bleaching or ironing (do people really iron their underwear?) Anyway, the last symbol did not show up on any standard for laundry tags that I could find. I'm left with using the synergy from my current job to define it. I'm going to assume it means do not drip engine oil onto the material, something I hope I will never do.

Tag Label


As I mentioned before, after years of practice putting on my own underwear, I had no problem putting these on. They actually felt quite smooth and breezy. I did not notice any abrasive spots or areas that would aggravate my skin. The waistband felt comfortable - not too tight and not too loose. The grip on my thighs was also adequate and they sit comfortably about 1/3 of the way between the crotch and the knee. I also had enough... ahem... room in the front as well.

I thought they looked fairly stylish though only a very few people will ever see me running around in them. I decided to test this theory out and tracked my wife down. I am not sure I can repeat the exact conversation but I'll try.

"Honey, can you tell me how these look on me?"

She raises an eyebrow so far up it quickly vanishes in her hairline.

"Why do you need to know how they look?"

"Well, I'm kind of testing these out..."

"And you want to know what other people are going to think your underwear looks like on you?"

"Well, no. Not when you put it that way. Look... just, what do you think?"

"They're underwear. They look fine."

"I'm really hoping for something more... official maybe? I'd like to quote you. I'm definitely not going to post a picture of me wearing underwear out on the internet."

I won't expand on what she said after that, other than it wasn't very flattering. Especially for a 48 year old guy standing around in his underwear with a goofy grin on his face. Still, she insisted that they looked fine and that is exactly what I'm going to (eventually) remember from the conversation.

She did hint strongly that she better not find them on the floor.

Underwear on the Floor


I did wear the Mountain Khakis Bison Boxer Briefs for a day and also slept overnight in them. I found them to be very comfortable and they did not interfere with any of my normal daily routines. At the end of the day, I had no signs of hot-spots, chaffing or aggravated areas. I did not experience any riding or binding. They stretched quite well to feel almost like a second skin. Overnight, I was also able to sleep without any issues.


The Mountain Khakis Bison Boxer Briefs are well constructed and lightweight. They are comfortable to wear and I'm looking forward to seeing how they perform on several upcoming camping and backpacking trips.

This concludes my initial report. The field report will be amended to this report in approximately two months from the date of this report. Please check back then for further information.

Lastly, I want to thank both and Mountain Khakis for letting me take part in this test.



Over the last two months, I have taken three trips. Temperature has ranged from 48 to 80 F (8.9 to 26.7 C) with some rain conditions overnight on two of the three trips. The first two trips consisted of base-camping with physical activities planned during the daytime. The third trip was a backpacking trip in one of the local state parks.


* Trip #1: Brighton Recreational Area - Brighton, Michigan USA - May 17-19, 2019. Temperature ranged from 48 to 70 F (8.9 to 21.1 C). There was 0.1 inches (0.25 cm) of rainfall on the first evening. While there was no backpacking, I did close to 20 miles (32.2 km) Mountain Biking.

* Trip #2: Private Property - Lake, Michigan, USA - May 24-26, 2019. Temperature ranged from 52 to 70 F (11.1 to 21.1 C). There was a massive thunderstorm the first night that dumped an estimated 0.23 inches (0.58 cm) of rainfall. During the day I went kayaking around a lake for several hours.

* Trip #3: Waterloo-Pinckney Recreational Area - Pinkney, Michigan USA - June 7-9, 2019. Temperature ranged from 57 to 80 F (13.9 to 26.7 C). There was no rainfall. Terrain was mostly dirt with gentle rolling hills. My backpack was 25.6 lbs (11.6 kg) and I hiked 15 miles (24.1 km) in 3 days.


While not really a trip, several days after posting my initial report, I was took part in a local 3.1 mile (5 km) race in our community as a fundraiser. The weather was a perfect 65F (18C). I am however an imperfect runner, which made me hot and sweaty while I limped to the finish line.

Thankfully, the Mountain Khakis Bison Boxer Briefs did an admirable job around my nether regions. I actually think this area was one section that did quite well. I did not suffer from chaffing nor did they ride up uncomfortably. For my legs, arms and just about everywhere else, I realized I am woefully unprepared this year for high endurance activities during the summer.

During the next two months, I went on three different camping trips, all of which included good opportunities to test out underwear.

For the first trip, I did several miles in a kayak around a lake. As I am not an expert kayaker, water tends to drain down the paddles and right into my lap. I only could have been wetter if I jumped into the lake. After I was done, I found the underwear to dry quite quickly (less than an hour) from my body heat. That night, I slept comfortably in the underwear.

For the second trip, I ended up going mountain biking with the local boy scout troop. This is only the second time I had ever been mountain biking and the boys really put me to the test as we pedaled screaming around tight corners. I was a hot, sweaty mess after the first hour. The boxers worked great though. I did not notice any restrictions to my movement, nor did I suffer from chaffing. Furthermore, the waistband fit perfectly and did not rub around my center section. The only improvement I would recommend is a built-in morphine dispenser to my bottom. My butt was sending signals of complaints and pain right up to my brain that lasted for days afterwards. I expect 20 miles (32 km) unprepared and unpracticed will do that. We might be doing this again in September and I am already groaning.
Resting my Poor Bottom after Mountain Biking

The last trip was a backpacking hike in nice weather. This trip was again with the scouts and they moved really fast - at times I think they were jogging up the trail with their packs on but as they were out of sight, I can't verify that. Either way, the Mountain Khakis Boxer Briefs handled everything fine. I still had no issues with chaffing and they rode just great. While somewhat disgusting, I also wore them for the entire weekend. They did not collect any noticeable odors.
Setting up Camp on Day 2 after a Long Hike

Upon completion of every event noted above, the boxer briefs were sent through the normal wash, which included a cold-cycle wash with normal laundry detergent, and the dryer set on regular, tumble-dry heat. I have not detected any shrinkage or degradation in the material.


1. Fit - they are snug to the thighs and waist but comfortable in the front area. This allowed them to ride comfortably on me as well.
2. Breathability - I did not suffer any chaffing or rubbing spots.
3. Fast dry time - each time they got wet (whether from water or sweat), they dried quickly.


1. None so far!


The Mountain Khakis Bison Boxer Briefs fit me great and I have enjoyed the comfort as well at the performance during some high sweating outdoor activities. I especially liked the lack of chaffing and other problems that develop with normal cotton underwear.

This concludes my Field Report. Thank you to both and Mountain Khakis for allowing me to test the Bison Boxer Briefs. The Long-Term Report should be completed within 2 months. Please check back then for further information.



* Trek #1: Cole Canoe Base - Alger, Michigan USA - June 22-23, 2019. Temperatures ranged from 52 to 75F (11 to 24 C). The ground is mostly dirt and camp is very flat with few hills. There is significant tree and brush coverage. I did base camping here only for the night.

* Trek #2: Denali National Park - McKinley Park, Alaska - USA - July 9, 2019. Temperature was between 80 to 85 F (27 to 29 C). I completed Triple Lakes Hiking Trail that is 9.5 miles (15 km) with a backpack weighing roughly 15 lbs. (6.8 kg). Elevation changes roughly 1000 feet (305 meters) over the course of the trail which was made up of mostly dirt with minor tree coverage.

* Trek #3: Manistee Trail Loop - Mesick, Michigan USA - July 17-19, 2019. Temperature ranged from 70 to 95 F (21 to 35 C). There was 0.35 inches (0.9 cm) of rainfall during a brief thunderstorm one night. The high humidity resulted in a heat weather index (real feel temperature) of 105 F (41 C) during the long hike out on the last day. Terrain was dirt and sand with minor elevation changes. My backpack was 28 lbs. (12.7 kg) and I hiked 25 miles (40 km) in 3 days.

* Trek #4: Manistee Trail Loop - Mesick, Michigan USA - August 1-2, 2019. Temperature ranged from 50 to 70 (10 to 21 C). Terrain was dirt and sand with minor elevation changes. My backpack was 25 lbs. (11.3 kg) and I hiked 8 miles (40 km) in 2 days.


In one word, I would say dryability. I am not even sure if that's a word but that is the word that comes to mind for me. Spacious would be another good word. That's a real word though. Unodorable. That's not a real word but I like it.

Okay, I like making up words.

I was able to test out the Mountain Khakis Bison Boxers Briefs over the last two months with great results.

It did not matter if I was in a heat wave in Alaska, in a heat wave in northern Michigan or a heat wave in southern Michigan.

Under some very warm conditions, I had piles of sweat pouring down my front and back which from there, ran right down into my shorts. The boxers collected it up and safely kept it away from my nether region. I also found that they dried very quickly. In spite of some long days, hauling a good-sized backpack over some bigger distances than I am used to, I never developed swampbutt or whatever the proper term for a painful rash from sweat and friction. I do speak from experience here and can say this underwear did its job much better than a pair of cotton underwear that I've used in the past.

I also was very pleased with how it passed my stringent "odor" test. I am not going to describe that particular test other than to say, it passed by not collecting or producing any noticeable scents. I will leave it at that.


I have sent the boxers though my general laundry weekly for roughly four months now. I have yet to see any signs of degradation, holes or wear. Furthermore, the waistband also still holds its elastic-ness the same as the first day I tried them on. They also still grip around the thighs.


I greatly enjoyed completing this test in spite of the hot weather we ran into. Thankfully, the briefs did a good job keeping me comfortable and making the trips great. I have tried to consider anything negative about them for a while and I just cannot come up with anything I do not like from a performance standpoint. Perhaps the only thing I can come up with is they are much more expensive than a normal pair of cotton underwear. On the other hand, for me I have found the performance benefits outweigh the cost when I am doing high-energy activities in the woods for days at a time. As such, I will continue to use this underwear and likely will be getting an additional back-up pair.

This concludes my long term report. I want to thank both and Mountain Khakis for letting me test the Bison Boxer Briefs.

This report was created with the Report Writer Version 1. Copyright 2019. All rights reserved.

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