Is the Exo Mountain Gear K4 the best hunting pack you can buy? Is it worth the money? To answer that question, I need to back up more than a few years to add some context about life before Exo Mountain Gear.
The pain was searing – a short distance into packing out half a spike bull, the flimsy buckle on the unpadded waist strap broke on my cheap “pack frame.” Far from the best hunting backpack, this essentially put all of the weight on my college-aged shoulders. I was left with two options: 1) drop nearly 1,200 feet down the mountain to the truck and get a different pack frame, then hike back up to retrieve the two quarters, or 2) suffer all the way down.
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All I could think about was getting off that steep, rocky ridge as fast as possible without seriously injuring myself. I made the same choice that day in 2008 that I bet many of you would have. There was absolutely no way I was going back up that mountain again. I may or may not have had a few “choice” words floating around in my head during that pack out.
Fast forward 16 years and the option to get that Idaho spike-only tag in November is long gone, but my memories of the pain from carrying half an elk are still remarkably vivid due to my subpar gear at that time. My “daypack” was not capable of hauling meat, and the pack frame I often carried was woefully unfit for carrying heavy loads. It seemed to be a harsh reality in that era that packing significant weight was never comfortable. This hunt and memory still make me chuckle every time I see that spindly spike bull on my garage wall.
Since that Pack Out….Searching for the Best Hunting Pack
Since my 2008 sufferfest, I went on the hunt for the best hunting pack I could afford and have filtered through a handful of different packs including well-known brands such as Cabela’s, Kelty, Badlands, Tenzing, and Eberlestock. Each of these packs certainly had their own unique strengths, but the results were oddly similar for me in that they just were not very comfortable carrying weight over 50-60 pounds.
While there certainly could have been some user error involved, the common issues I ran into were the lack of torso adjustment, insufficient lumbar support, and inadequate waist padding/straps which made it difficult to use them for all of my desired purposes on day hunts, backpacking trips, and packing meat. It seemed they might excel in one use case while lagging behind in another. Eventually, that is what pushed me over the edge to venture out and continue trying new packs.
Enter Exo Mountain Gear. I switched over to the K2 in 2016 and greatly enjoyed that pack. The ability to hunt out of it and also be able to haul meat was a game changer! I then used the K3 for several years and figured it had to be one of the best packs out there.
My first reaction when I saw the new Exo Mountain Gear K4 pack was “is it worth it?” That question kept rattling around in my head. I initially dismissed the K4 and figured any updates had to be minimal and likely not worth the investment to upgrade from my current K3. Eventually, I decided I had to find out for myself.
After abusing the K4 for an entire season, which included training hikes, backpacking, scouting, a full hunting season chasing mule deer and elk in both Colorado and Idaho, along with several of the heaviest packouts I have ever tackled, I can confidently say I have an answer to my initial question. More to come on that later. For now, let’s dive into the details of this review, talk specifics of the Exo K4 3600, cover my uses, and discuss takeaways from well over 40 days of use in the field in 2023.
Exo Mountain Gear Background
Since Exo Mountain Gear was founded in 2014, it has quickly become well known in the hunting and backpacking community for producing a high-quality product made in the USA and backed by tremendous customer service. Exo’s mission is to build the best hunting pack available for the mountain hunter.
Exo is a small company owned and operated by hardcore hunters, which is evidenced by their ongoing commitment to testing and improving their products. Once I decided to take the plunge on a K4, I could not wait to get my hands on this pack and see what it could do.
Pack Fitting – Exo Mountain Gear K4 Pack
Having previously used the K3 4800 for day hunting and backpacking trips of up to 6 days, I opted to try the K4 3600. My intent was to use this pack for all of my day hunts and backpacking trips in that 3-5 day range. Note that each of the K4 bags are interchangeable, so you have the flexibility of being able to swap them out if needed.
One of the things that Exo Mountain Gear did in their pursuit of building the best hunting pack available is to add customization to the fit. The K4 pack system is a bit different than previous models in that you need to get familiar with your individual dimensions prior to ordering, including deciding on the hip belt size (measuring your iliac crest) and frame height (based on your body type/hunting style).
These sizing options each have a range within their fit and the unique modifications make perfect sense as they allow for individual adjustment of the pack based on the user’s body shape. Details and additional videos on sizing can be found here in the Exo Pack Size Selection Videos.
Materials – Exo Mountain Gear K4 Pack Review
Exo Mountain Gear sources USA-produced fabrics and completes the sewing, building, and shipping of their packs in Boise, Idaho. Exo Packs are built with 500D Cordura (500D = fiber thickness of individual threads) and backed with a polyurethane (PU) coating to ensure long life of the fabric and aid in water resistance. Additionally, packs are treated with a durable water repellent (DWR) finish to minimize water absorption.
High quality closed cell foam, premium buckles built with Acetal (widely used in a variety of industries for its high strength), and gold standard zippers made by YKK round out the base materials found in Exo Mountain Gear Packs.
I could spend an excessive amount of time on the attention to detail and build quality, but in summary, these packs are built to take serious abuse in tough conditions. Their dedication to quality and keeping production in the USA and is another reason they are one of the best hunting packs available on the market today. If you care to learn even more about the nitty-gritty of the materials and how Exo Mountain Gear makes their packs, read on here.
Specs – Exo Mountain Gear K4 Pack Review – Best Hunting Packs?
If you have read any of my reviews the past couple of years, you may have noticed I am on a mission to evaluate everything in my pack. I work to upgrade/optimize as often as possible with the end goal of minimizing total weight while not sacrificing on core essentials. After completing an upgrade of my sleep system, the Exo K4 pack system was another obvious choice to improve my backcountry experience and pack weight.
Here are the specs of the Exo K4 3600 with the lid, a large hip belt, and 26.5” frame.
| Exo K4 3600 Specs | |
|---|---|
| Fabric | 500D Cordura |
| Frame Material | Carbon stays |
| Foam | Closed-cell foams with cross-linked ethylene copolymer |
| Main Bag Size | 3,620 ci |
| Lid Size | 648 ci |
| Total Capacity (bag & lid) | 4,268 ci |
| Buckles | Duraflex |
| Zippers | YKK |
| Weight (Bag, frame, lid, hip belt, shoulder harness) | 5 lbs 8 oz |
| Weight (Bag only) | 2 lbs 1 oz |
| Weight (Frame only) | 2 lbs 15 oz |
| Lumbar Material | Superfabric (600D Polyester base) |
| Shoulder Harness | Spacer Mesh |
| Expanded Dimensions | 8″ x 37″ x 10.5″ |
| Compressed Dimensions | 2.5″ x 25″ x 10.5″ |
There was a noticeable difference from my K3 4800 in how compact the K4 3600 bag is. The materials on the pack are very efficiently designed with no unnecessary fluff. Additionally, it is a touch easier to cinch down the 3600 for day hunts when the expanded space is not needed.
In addition to the above, I opted to add on the following Exo K4 accessories to make this the best hunting pack configuration for my needs:
- Exo K4 Insulated Nalgene Holder
- 3.6 oz, 4” x 8”
- Exo K4 Hipbelt Pouch
- 3.4 oz, 7” x 5” x 2”
- Two Exo K4 Stash Pockets
- 0.7 oz, 8” x 6.5” x 0.5”
- Exo K4 Crib Load Panel
- 4.4 oz, 9” x 26”
- Exo K4 InReach Mini Holder
- 0.8 oz, 1.5” x 2.25” x 3”
- Exo K4 Quick-Release Rifle Carrier
- 2.8 oz
All in, this put my base pack weight at 101.6 ounces (a touch over 6 lb, 5 oz) for archery hunts and 104.4 ounces (~6 lb, 8 oz) for firearm hunts with the rifle carrier attached. To confirm accuracy of listed weights from the website, I took my pack with the above accessories (not including the rifle carrier) and weighed it at 6 lb, 4 oz, roughly one ounce under the total listed weight from Exo’s website.
This base weight under 7 pounds is right there on the front line for being one of the lightest on the market for high-end, fully-equipped meat-hauling packs. When I settled on ordering the K4 3600, I was a little bit nervous that the reduction in total cubic inches from my K3 4800 might make it challenging to fit all of my gear for backpacking trips.
However, with two hip belt pouches (approximately 70 cubic inches each) and a Nalgene Holder (approximately 80 cubic inches), that gives the K4 3600 a true size of approximately 4,488 cubic inches. This number also does not account for getting a little creative and using straps on the exterior of the pack to cinch down gear like my tent, sitting pad, and tripod that I am not particularly worried about getting dirty or wet.
Field Notes On Accessories – Exo Mountain Gear K4 Pack Review
EXO K4 INSULATED NALGENE HOLDER
The Exo K4 Nalgene Holder is my personal favorite addition to the Exo Mountain Gear K4 pack system. While I have long used a hydration bladder (the K4 still has that compatibility), I found that I personally prefer NOT sucking through a hose.
I find it easier to stay hydrated throughout the day (especially in early season when hunts tend to be warmer or late season when hoses tend to freeze) when I can utilize a Nalgene with either water or Wilderness Athlete Hydrate & Recover to chug down larger quantities of liquids. While the Nalgene bottle does sit on the waist strap behind you a bit, I found it very easy to grab and drink, then put back in the holder with one hand.
EXO HIP BELT POUCHES
The Exo K4 Hip Belt Pouches are nearly identical to past versions, except the ammo cartridge insert is no longer offered. I got a little creative on my K4 and used Velcro tabs in one of my new K4 pouches to install my K3 ammo cartridge insert on the K4 pouch. I would personally love to see future versions of the pouches again include the option for the ammo carrier as this was a feature I had come to appreciate.
EXO K4 PACK STASH POCKETS
The Exo K4 Stash Pockets are compatible with both the K3 and K4 systems and come in very handy for storing odds and ends. I prefer to have one in the lid for storing my tags, charger, cords, car keys, etc. and another in the bag for my first aid items, extra batteries, rope, etc. I am a big fan of having my pack organized so I can quickly find what I am looking for and the Exo K4 Stash Pockets help accomplish this.
EXO K4 CRIB LOAD PANEL
The new Exo K4 Crib Load Panel is noticeably different from the K3 setup with where it attaches at the base of the pack. The K3 seemed to have a bit more capability to keep meat slightly “lifted” on the pack, while the K4 Crib Load Panel really allows for quarters to be cinched down more effectively in place. My first pack out with the K4 required a bit of “situating” on the front end to get quarters centered on the pack properly before tightening down the Crib Load Panel.
EXO K4 INREACH MINI HOLDER
The addition of the Exo K4 InReach Mini Holder is a close second in the standings of my favorite new accessories. Several years ago, I arrived back at camp with only the carabiner and a little fabric from the Garmin InReach Mini strap attached to my K3. I still have no idea how but I managed to rip off my Garmin InReach Mini while navigating my way through a thick patch of willows.
This was an expensive mistake and one I do not want to make again. I was very excited to see this new accessory option on the K4. In an absolute worst-case scenario of a fall or sudden injury where you need to call for help immediately, the placement is ideal in that your InReach is easily accessible while wearing your pack.
EXO K4 QUICK RELEASE RIFLE CARRIER
The also new Exo K4 Quick Release Rifle Carrier grew on me over time. It took a little bit of getting used to, but it firmly secures your rifle and allows for easy hiking or wearing the pack/rifle on a motorcycle or ATV. My only wish with the rifle carrier design is that it would be possible to put the rifle back on the carrier and strap it in without needing to take the pack off.
While taking off the pack is a minor inconvenience, I have used other aftermarket products that allow for the pack to remain on while the rifle is taken on and off and would love to see that versatility in the future.
Note that all of the K4 accessories utilize the universal MOLLE (Modular Lightweight Load-carrying Equipment) system. This is a significant difference from past iterations of Exo Mountain Gear packs as older accessories are NOT transferable to the K4 (except the Stash Pockets). The additions of these new accessories was a real improvement and again solidified them as one of the best hunting packs out there.
The Testing – Exo Mountain Gear K4 Pack Review
I could not wait to put this pack to the test and see how it handled. I am a gym rat and maintain my lifting/cardio routine at my local gym year-round. Beginning in spring here in Northern Colorado, I skip the gym on my planned cardio days and instead head outdoors 2-3x per week for weighted hikes with 70 pounds.
The rotation of weightlifting 2-3x per week paired with sunrise hikes with my Exo 2-3x per week helps avoid the monotony of only being at the gym. Weighted hikes have also greatly helped to ensure my feet, ankles, knees, and hips are not in pain after a few days when I hit the trail for my summer scouting and fall hunts.
When My K4 3600 arrived and I moved my sandbag from my K3 to my K4, I could immediately tell a significant difference in the rigidity of the pack. The K3 was fantastic, but my biggest complaint was that it tended to “slip” a bit at the waist for me over time, requiring small adjustments or shifting the weight back up.
After getting my K4 adjusted to the proper fit, I did not have to make additional adjustments throughout my usual 4-mile hikes. I also noticed that the K4 sits a touch higher which aids greatly in ensuring full range of motion for my hips, thereby reducing fatigue. The rigidity of the pack paired with the larger waist pad is a game changer.
The K4 waist pad is made with “Superfabric” (600D polyester base with raised texture) and offers fantastic, breathable grip. The noticeably stiffer lumbar pad fits to your body shape over time and prevents slippage. Note that if you find the foam too stiff for your liking, the folks at Exo Mountain Gear are happy to provide a softer foam you can insert into the lumbar pad. Another example of fantastic customer service.
As spring moved into summer, I was able to take my Exo Mountain Gear K4 3600 pack on multiple backpacking trips and archery shoots putting it to use in the high country. The Exo K4 3600 continued to impress in a wide range of conditions.
From early September through mid-November, I was fortunate to spend over 26 days hunting for mule deer and elk. My archery season began with a six day hunt in Colorado. While no tags were filled, I gained valuable experience in a new unit and utilized the Exo K4 3600 to comfortably carry camp on my back for 2-3 days at a time allowing my hunting partner and I to stay mobile and explore multiple drainages.
With proper planning, I did not experience any issues with having enough space in the K4 3600. I was thrilled to keep my total pack weight multiple pounds lighter than the year before and easily could have extended out to 4-5 days at a time with the 3600.
Next up, I spent 7 days in late September chasing elk in Idaho. On day two, we located a small herd over two miles away across a large drainage. After putting them to bed mid-morning, we hiked from our glassing location several miles around the mountain and up the backside to get in position.
Seven hours after we had spotted the elk, we were in perfect position and had executed our stalk keeping the late afternoon thermals in our favor during our approach.
The setup was classic with the shooter perched above an obvious game trail leading to a timber patch and me as the caller back about 60 yards near the low spot of a ravine. The bull would have to crest the small ridgeline to see my position.
We opted to use soft cow calls as we were confident he was not the dominant bull in the area and he only bugled occasionally. A bit of sweet talking and he came to investigate. I had been attempting to cast the sound lower on the mountain away from where we believed the bull to be bedded.
This worked to perfection to draw his attention away from the danger above and the bull crested the ridge peeking down the canyon trying to get a look at where he thought the calls were coming from. The setup was textbook, and the bull presented a 40-yard broadside shot. My heart skipped a beat as I heard the classic “thwap” of the arrow connecting. My brother had executed the shot and the bull was down for good moments later.
High fives and hugs were exchanged, and we called for reinforcements. It was a family affair as two of my brothers, my nephew, and I enjoyed a moonlit Idaho packout. The Exo K4 pack again performed extremely well and made my 124-pound pack feel as comfortable as it possibly could for the duration of the packout.
This was my first time hauling elk quarters in the Exo K4 3600 and it did take me a bit longer to get meat situated on the pack with the Crib Load Panel. With a little adjusting to get the weight centered properly and tightened down, though, that 124 pounds felt more like 70 or 80 on older packs I have used.
Just under three weeks later, I returned to Idaho to try and fill my two Idaho mule deer tags. We glassed up a lot of deer and smaller bucks the first few days but nothing we were willing to pull the trigger on. On day four of this planned six-day hunt, I was able to connect on my first ever “double” on two Idaho four points with my brother at my side. While I am sure these bucks will not be making any record books, the memory and the meat in the freezer is truly a trophy to me.
My brother and I each carried an entire quartered out buck with all the loose meat – pack weights were 125 and 134 pounds respectively (verified at the trail with a scale) with the haul being nearly 4 miles and 2,200 feet of elevation one way. I can honestly say that I do not think this packout would have been physically possible for me using some of my older packs, but the K4 was up to the task.
Last, but not least, I had a full 7 days planned for a solo deer hunt during Colorado’s third rifle season. I made up my mind before this hunt that I would find a mature buck or I would take the tag home with me. The morning of day one I blew a great opportunity and missed a beautiful 4×4 after rushing the shot when I should have been more patient.
My resolve was tested multiple times over the next several days as I was glassing up lots of deer, including many immature bucks and a handful that were just on that fringe of “almost.” Needless to say, I tried very hard to grow them up a bit, but ultimately kept reminding myself of my end goal – mature buck or tag soup.
The unit I was hunting has great deer numbers and the mid-November timeframe would, in theory, mean the bigger bucks should soon be joining does. I knew if I stuck with it, there was a chance at finding a mature deer. On the evening of day five, I located a buck doing the iconic mule deer “lip curl.” When I got the spotting scope zoomed in, I immediately knew this was a buck I wanted to pursue. With an hour of legal light remaining, a bit of a frantic stalk ensued.
After closing the distance from about a mile away, I found myself just over 300 yards from the group of deer. I quickly laid down my Exo Mountain Gear K4 Pack to help get the needed elevation for the steep uphill shot. Paired with my Swagger SFR10 bipod, it was just enough clearance off the ground for a shot. I then got my Crosstac Ultralight Rear Rest set up and switched over to my spotting scope and started scanning over the dozen or so deer to try and relocate the target buck.
It did not take long to find him, so I dialed in the range on my Zeiss Conquest V4 6-24×50 and double checked the time: 24 minutes of legal light to spare. As I readied for the shot, the buck was chasing a hot doe and soon presented a quality broadside angle. My rest was rock solid, and I knew it was likely now or never.
After the shot, the buck quickly ran out of sight behind a fold in the terrain. I watched for several minutes as the remaining herd of does and smaller bucks stared down into the ravine where I had last seen him run. I was fortunate on this hunt to use an On Glass Digiscoping Adapter on my Kowa TSN 773 spotting scope to film the shot. After the opening day mishap, I knew if I was to take a shot just before dark (especially on a solo hunt), I wanted to be absolutely sure I could execute a clean kill.
It was a huge relief to be able to immediately replay the footage to see that the shot was true and the buck was hit hard right behind the shoulder. Once the magnetic base of the On Glass adapter is installed on the back of your phone, no further modification is required as the magnetic alignment allows for quick use. Slide the adapter over the eyepiece of the spotting scope, pop your cell phone on via the magnet, hit “record”, and you are all set.
In this case, a few of the does pinned me down right before I shot, so time was of the essence. Getting the On Glass adapter on the scope and my phone attached and rolling took all of about 10 seconds. As an added bonus, I love having the footage so I can relive this moment over and over again. On Glass was founded by a Special Ops Vet and they make a fantastic product.
Feeling confident the buck was down and with light fading, I made my way up the mountain to come face to face with one of my best bucks to date. I sat on that hillside for a few minutes thanking God, taking it all in, and counting my blessings.
A group of nearby coyotes began howling and oddly, a large herd of elk began talking back and forth after dark with hundreds of bugles and constant cow calling/estrus whines. This was something I certainly did not expect to experience on a mid-November hunt but it was the cherry on top of an incredible experience and one I will not soon forget.
I was once again thankful to have my Exo Mountain Gear K4 3600 for this pack out. This was by far the largest-bodied deer I have ever taken, and my pack weighed in at over 142 pounds. Exo’s website states that the K4 is rated to perform up to 150 pounds, and after packing just under that I believe it! I was also extremely grateful that my old pack frame from 2008 was nowhere to be found for this pack out!
Takeaways – Exo Mountain Gear K4 Pack Review
After putting my K4 pack to the test in a wide variety of uses over the past 7 months, I have a firm grip on this pack and what it can do. Exo packs are not cheap and the all-in cost for what I chose (pack and accessories) is just over $900. Not a small chunk of change by any stretch.
In the scheme of hunting gear, there are three things I absolutely will not compromise on: my weapon, my boots, and my pack. I firmly believe that this pack is an investment that will pay for itself multiple times over and is a piece of gear you will be able to use for many years. Here are a few of my personal takeaways.
Minor improvements I would love to see:
- The lid tends to be a touch floppy when the pack is not full. This may be unavoidable, but I would love to see it have the capability to cinch down a bit tighter.
- I was sad to see the ammo carrier not available as an option for the K4 Hip Belt Pouches. I found it very useful on my rifle hunts.
- It would be an added bonus if the rifle could be re-installed on the carrier without having to take the pack entirely off.
Pack Strengths:
- The rigidity is a game changer! This pack will carry as much weight as you are physically able to.
- The larger/improved waist strap is very comfortable and truly helps keep all the weight off your glutes and on the hips where it should be.
- The design and functionality of the Exo K4 3600 is exceptional. It is obvious that this pack was built for hunters and every detail was thoroughly thought out.
- The accessories were extremely well built and very useful. Again, I loved the Nalgene holder and InReach case specifically.
Conclusion – Exo Mountain Gear K4 Pack Review
Back to my original question – “is it worth it?” In past years with other packs, I have hauled an entire deer or half of an elk multiple times – very similar to what I did during the 2023 hunting season. I can now 100% confidently say that, for me, the answer is a resounding “yes!”, the Exo Mountain Gear K4 pack IS worth it!
This pack is on another level and carries extreme weight better than every other pack I have tested. Over and over, I was extremely impressed by the functionality, versatility, and brute strength of the Exo Mountain Gear K4 Pack system. After successfully packing loads off the mountain of 124, 135, and 142 pounds throughout the season, I am convinced that I will physically fail before this pack does.
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