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  • Writer's pictureAllen Crater

Gear Review: Exo Mtn Gear K4 5000 Pack System

Updated: Mar 29

Hunter carrying a pack through the snow in the mountains


I've been a backpacker for nearly 30 years – hiking trails across the country from New Hampshire's Mount Washington to Oregon's Mount Jefferson, all throughout the Sierras, the Rockies, the Winds, the Sawtooths, and extensively in Montana's various ranges. I started with a Kelty external frame pack in the early '90s and eventually converted to internal frame packs from Osprey, which I've always been happy with.

I've also been a hunter since age 12 – at least a Michigan hunter. It wasn't until my oldest son, Kyle, moved to Montana for school that an "out-west", backcountry hunt even seemed liked a possibility.

My first year chasing mule deer in Montana with Kyle I used my tried-and-true Osprey backpack. It had always been a capable companion – comfortable, roomy, and well laid out – at least for a traditional backpacking trip. But for hunting purposes it had limitations, the most glaring being the lack of a meat/load shelf for hauling out game (which, unfortunately, was not needed on this first hunt anyway).

Hunter with a pack in the mountains

The Osprey pack on my first Montana Hunt

Heading into my second Montana hunt, I went on the search for a proper backcountry hunting pack – evaluating a number of brands: Stone Glacier, Mystery Ranch, Eberlestock, Kifaru, and even Sitka and Kuiu. I talked to a lot of friends that had personal experience with each, and I read a ton of reviews. While each of these packs had favorable aspects and their own group of loyalists, I finally settled on Stone Glacier's Sky Talus 6900 from the bunch, and spent the summer and early fall training with it before taking it to hunt.

Stone Glacier is a justifiably well-respected brand and they make great products, but sometimes, much like a good pair of boots, "the right pack" comes down to individual fit and personal preference – despite wanting to love the Sky Talus, I really didn't. My complaints essentially came down to three issues: cost, complexity, and layout.

Hunter carrying a pack with a Mule Deer in the mountains

The Stone Glacier pack on my second Montana hunt

Cost - At a starting price of nearly $700, plus the need to add various accessories (inside organization pockets, belt accessory pockets, and a rifle sling) the Sky Talus ended up running me around $850 – a pretty damn sizable chunk of change. If I'm going to spend that kind of money I expect to LOVE what I purchase.

Complexity - The Sky Talus had a LOT of adjustments and configurations which could, of course, be a positive, but for me they were a negative. There were SO MANY straps and buckles and configurations that it often left me feeling frustrated. Now, I will admit that much of this trouble was likely due to user error (or user denseness). In fact, I had one of the Stone Glacier employees patiently walk me through the various configurations in person...twice...and I was still confused. So, while I'm sure, with more regular use, the adjustments would become second nature (as evidenced by the SG employee), for me the darn thing was just too complicated.

Layout - Coming from a more "pure backpacking" background, after week-long backcountry use I didn't really love how the Talus laid out. The main compartment was relatively thin (due, I think, to the load-shelf space) and didn't stow gear the way I expected. The two zipped side pockets were very large/voluminous but somewhat awkward and non-functional for how I pack – being very tall and tubular and not really the right shape for many items (maybe spotting scope and tripod?), and I found the lower open-topped side pockets too shallow to effectively carry my water bottles. Generally speaking, I just didn't love how the pack organized my gear.

Two men carrying backpacks in Wyoming

My buddies with their overloaded Exo K3 4800s in Wyoming

August of the following year found me on a backpacking/fly fishing trip in Wyoming with two of my buddies who also do a lot of hunting around the country. They were both carrying the Exo Mtn Gear K3 4800 packs and, when I asked for input, had really good things to say. Up to that point, Exo hadn't been on my radar, but after talking to them, doing more research, and reading this on the Exo website: "We have obsessed over every detail of our bag designs, making sure they are simple and easy to use, but haven't sacrificed in versatility or features," it quickly moved to the top of my list.

Early in 2023, just as I was about to pull the trigger on the K3 4800, Exo launched their new K4 series. Their new K4 frame boasted the culmination of 20+ years of backcountry hunting experience, 10+ years of pack design experience, and 3+ years of focused design, development, and in-field testing by over 150 different hunters. While newer doesn't always mean better, this was pretty compelling, and my mind was made up. I purchased the K4 5000 pack system ($700) for my upcoming OTC Elk hunt in Colorado with my two sons, and began training with it.

I also added the following accessories to my K4 5000 pack:

For me, each of these accessories made great additions to the system. The bottle holder was very handy and integrated right into the hip-belt, the pouches added convenient and accessible storage for small items I wanted to keep at hand (wind checker, phone, snacks, knife, chapstick, hand warners, etc), and the quick release rifle carrier also integrated directly into the straps and hipbelt (opposite of the Nalgene Bottle Holder), was easy to install, and easy to deploy. The InReach Mini holder probably wasn't needed (you can attach the mini with a carabiner), but I liked having it handy/accessible, yet secure and out of the way.

a hunter carrying a pack down a mountain at sunset

The K4 5000 day one in Colorado


The K4 5000 frame weighs less than three pounds, and the whole outfit (frame plus bag) has a total weight of five pounds, 13 ounces. It offers a 5,658 cubic-inch load capacity and 150-pound carry rating.

The pack incorporates a number of intuitive, hunter-specific features into the design:

All K4 Bags feature roll-top access into the main bag. The roll-top also allows you to expand/contract the pack volume as more/less space is needed. In addition to the roll-top access into the main bag, the K4 5000 has horseshoe-shaped front zip access.

a backpack after carrying out an elk

There's also a zippered front panel built with specialized stretch fabric offering quick and secure access to items you need throughout the day, such as an extra layer, a glassing pad, gloves, or similar items.

Every K4 Pack features full-length, zippered side pockets on both sides of the bag. The pocket is pleated, offering spacious storage for full-size spotting scopes, even when the main bag is full.

Both sides of every K4 bag feature top-entry stretchy side pockets that work great for tripods, trekking poles, water bottles, and the like. The pack's upper side compression strap keeps tall items secure. These side pockets are "dual-compartment", also featuring a quick-access compartment – keeping essential items easily accessible while you are wearing the pack. This works nicely for headlamps, gloves, phone, snacks, or other commonly used gear.

The lid offers two storage compartments that add nearly 650 cubic inches to the pack's capacity. The lid also works great as a compression panel when packing out a skull and antlers at the end of a successful hunt.

The K4 5000 also features a dedicated water bladder compartment. The waterproof lining and bottom drain grommet keep your gear dry if your bladder leaks. The area also works great to keep wet items (such as a tent fly) separate from the dry gear inside the main bag.

The bag can be quickly separated from the frame for carrying out game. Compression straps built into the frame offer secure compression for quarters, boned-out meat, load cells, or similar items.

Laser-cut MOLLE panels on the hip-belt and shoulder harness offer secure mounting of K4 Accessories, as well as third-party MOLLE-compatible accessories and holsters.

Integrated compression straps on the face of the pack work great to secure your bow or rifle to the bag (if not using the rifle carrier accessory).

The K4 frame can be interchanged with several different bags beyond the 5000, including the 2200, 3600, and 7200.

Two hunters carrying backpacks through the snow in the mountains

What I like:

Simple, easy, non fussy–design philosophy. I think the thing I appreciated most about this pack was the overall design and simplicity. The layout, the pockets, and the overall organization really made a lot of sense on this pack, the accessories were smart and intuitive, and the adjustments were easy (including use of the meat shelf). Additionally, Exo has a ton of online videos and really good customer support to help with fit, features, adjustments, and accessories.

Speaking of fit, you can really dial in the fit of the K4, with four different frame height options (22" - 26.5"), five hip-belt sizes, and a number of micro-adjustments for fine-tuning. I'm 6',1" and fell right in between the 25" and 26.5" frame sizes on the chart. I ended up ordering the 26.5" based on my longer torso, but might have been better served the 25". That being said, I was able to get the fit dialed in using the pack adjustments.

Load carrying. The K4 frame is designed with the rigidity required to support the heaviest of loads without any deformation, barreling, or instability, and the unique frame shape and custom carbon fiber stays enable torsional flexibility that allow the frame to move with you in the rough terrain. Once I got the fit and adjustment dialed, I can honestly say this pack handled weight better than any I've previously owned. I spent most days carrying 65+ pounds comfortably, and it managed the pack out of my son's bull easily.

Durability and clean up. Backcountry hunting is rough on gear – clothing, equipment, boots, and packs. In fact, after just one week on a previous hunt, my Stone Glacier pack was starting to show some minor wear (small holes, etc). The MIL-SPEC 500d Cordura used on the 5000 bag held up well to harsh weather and backcountry abuse and was easy to clean up after the pack out.

Built by hand in Boise, ID, USA , and backed by a lifetime guarantee. While I don't exclusively buy products made in the U.S., I try to as often as I can. It's nice to know that I am carrying a pack that was developed and produced right in Idaho.

A hunter climbing a mountain in the snow while carrying a backpack

What I don't like:

Cost. While there's not much I didn't like about the K4 5000, it still isn't cheap, coming in at around $700 plus any accessories. But, I will say that this $700 felt more well spent and appropriate to the end product than the last one, at least for me.

Different bottom straps? One thing I struggled with on this trip was where to stow my (stupidly big) glassing mat (essentially a super cheap sleeping pad I brought along just for glassing). My pack was pretty maxed out between a tent, sleeping pad (inflatable), sleeping bag, stove, fuel, water (and filter), food, clothes, kill kit, med kit, spotting scope/tripod and rifle. That being said, I never found a great spot for the extra glassing mat, though I made it work.

Exo Mtn Gear K4 5000 pack resting against a tree in the snow

Perfect For: The K4 5000 might just be the perfect do-it-all hunting pack, featuring intuitive, easy-to-use design, a variety of options and adjustments for the ideal fit, superb weight-carrying ability, durable, easy-to-clean fabric, smart accessories, and a lifetime warranty. The pack is plenty for a week-long backcountry hunt and can compress down for day use, plus the K4 frame can be used with other bag sizes ranging from 2,200 to 7,200.

Stars: 5 out of 5

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