Zpacks Arc Haul UltraEPX 60L Backpack Review
Updated:
Jan 20, 2025
Comfort
Organization
Weight
Durability
Water Resistance
Sustainability
Weight
1 lb. 7 oz.
Stated Load Limit
40 lb.
Fabric(s)
Ultra 100X & Ecopack EPX 200
Adjustable Torso
Yes
# of Pockets
3
Access
Top
Capacities
40, 50, 60, 70L
Included rain cover
No
Pros
Cons
Zpacks Arc Haul UltraEPX 60L
For this season's top models, see our guide to the Best Backpacking Backpacks.
Despite its ridiculously low weight, the Arc Haul UltraEPX can comfortably support loads up to around 30 pounds, which is a notable feat. However, like many ultralight packs, performance starts to suffer when it’s stuffed to the gills. The pack’s suspension consists of two thin carbon fiber stays, an ultralight material that shaves ounces off the Arc Haul’s weight but doesn’t distribute the load as well as a traditional metal frame. What’s more, we found the shoulder straps and hipbelt trended towards being squishy and lacked structure. For comparison, they offer less cushioning and support than the Granite Gear Crown3 60, but more than the Hyperlite Mountain Gear Southwest 55 (perhaps the Arc Haul UltraEPX’s closest competitor in the capacity-to-weight category).
I tested the Arc Haul UltraEPX on a three-day, 22-mile excursion into Seven Lakes Basin in Olympic National Park, stuffing it with 35 pounds of gear, including a bear canister. The first and second days on the trail were tough; despite the pack’s suspended backpanel design, the bear canister dug into my back and made my time on the trail feel burdensome. I finally became proficient at the required Tetris packing game by the third day, which allowed the suspension to work correctly and maintain separation between my back and the contents of the pack. All in all, the Arc Haul performs best under loads of about 30 pounds, well below its manufacturer-stated max weight of “around 40 pounds.” This is still impressive for a backpacking pack this light, especially since the backpackers most likely to carry the Arc Haul are minimalists and thru-hikers who have their kit pared down to the essentials.
The Arc Haul has a noticeably pared-down pocket setup, even for an ultralight backpacking backpack. It features a mesh dorsal pocket and two side pockets, but nothing else (not even an internal reservoir pocket). While Zpacks sells add-on hipbelt pockets, shoulder strap pockets, and other accouterments to help with organization, they cost extra. In my opinion, hipbelt pockets are a must for backpacking and I was bummed not to have them on my hike in the Olympics. However, I was very impressed with the large mesh stash pocket: It’s one of the largest such compartments I’ve come across and it was able to accommodate layers, snacks, and more. I stored my Nalgene water bottle and tent poles in the side pockets, which could also fit an ultralight tent in a pinch.
At less than 1.5 pounds for a size medium, the Arc Haul UltraEXP is one of the lightest full-suspension packs on the market, and the lightest pack I’ve carried (it undercuts the ultralight ULA Circuit by over 1 pound). For backpackers who have their base weight absolutely dialed, the benefits of such a simple pack are manifold: more miles, happier feet, and fewer sore backs. In that sense, the Arc Haul is great for thru-hikers, minimalists, and light-pack aficionados who geek out on counting ounces and carry only the essentials.
Of course, there are drawbacks to all those shaved ounces. If you’re not an expert packer, the Arc Haul UltraEPX’s design can cause more soreness, not less. Its organization may be a challenge for backpackers who are used to more pockets, and it may seem less comfortable if you’ve only carried heavily padded packs in the past. Still, for the relatively small niche of backpackers that it’s designed for, the Arc Haul’s weight (or lack thereof) is its most desirable attribute.
For the “UltraEXP” version of the Arc Haul, designers employ two different fabrics. The inside of the main compartment is made from Ultra 100X, a relatively new 100-denier material made from Ultra High Molecular Weight Polyethylene (UHMWPE) that’s laminated to a waterproof lining. The perk of Ultra 100X is a tear strength that far outperforms its tissue-paper weight—the company claims it’s even more durable than Dyneema, which has long been the standard bearer in this category.
On the outside, the Arc Haul UltraEPX features Ecopack EPX 200, which gives the pack its pop of color. This recycled polyester fabric is almost double the thickness of Ultra 100X, but it’s less durable (Zpacks notes its tear strength at 33.1 lb. vs the 100X’s 69.4 lb.). If you don’t think the bright colorways of the UltraEXP are necessary, the standard Arc Haul Ultra is made entirely from Ultra 100X, costs the same, and is an ounce lighter.
Although there are more durable ultralight backpacking packs out there, I appreciated that the Arc Haul UltraEXP’s materials were lightweight and slimmed down. Only time will tell how the buckles and seams will hold up, and the small buckles on the roll-top and chest strap make me nervous about their longevity. Also, this pack has a lot of daisy chains and stitching that could unravel as the miles pile up.
One of the highlights of both Ultra 100X and Ecopack EPX 200 is that they’re fully waterproof. Conditions in the Olympics were hot and dry so I didn’t get to test out the waterproofing on the trail, but when I put the Arc Haul UltraEPX in a shower test, it held up to sprinkles of water for many minutes with no soaking through. If you close the roll-top correctly and make sure the material doesn’t have any openings, the Arc Haul will keep your gear dry for anything short of submerging the pack in a river. In addition to its lightweight durability, the high level of waterproofing is one of the primary selling points of these niche materials and a reason why someone would splurge on a Zpacks’ design.
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Longevity
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PFAS-Free DWR
Durable water-repellent (DWR) finishes can contain PFAS (per- and polyfluoroalkyl substances). These highly persistent “forever chemicals” are used in outdoor gear for their strong resistance to water, oil, and heat, but are linked to environmental contamination and a range of health concerns. A green check mark indicates the product uses a PFAS-free DWR, while a red X means the DWR contains PFAS.
Recycled Materials
Recycled materials are prevalent in outdoor gear, with nylon, polyester, wool, and down among the most common, but the composition varies widely. A green check mark indicates the product is made with a substantial amount of recycled materials (100% recycled or the core fabric that makes up most of the product is recycled), a yellow check means it contains a moderate to small amount of recycled materials, while a red X means there are no recycled materials in the product.
Bluesign Approved
Bluesign Technologies, based in Switzerland, operates a third-party textile management system that ensures materials are manufactured to strict environmental, chemical, and worker safety standards. A green check mark indicates a product is either a Bluesign Product (contains at least 90% Bluesign-approved fabrics and 20-30% Bluesign-approved accessories) or features a significant amount of Bluesign-approved materials. A yellow check mark means it uses some Bluesign-approved materials but less than the aforementioned category, and a red X means there are no Bluesign-approved materials in the product.
Responsible Manufacturing
This criterion evaluates a brand’s commitment to fair wages, safe working conditions, and reducing environmental impact through certifications and programs like Fair Trade Certified, Fair Wear Foundation, Worldwide Responsible Accredited Production (WRAP), and the Fair Labor Association, while also recognizing brands that manufacture primarily in the U.S. or Europe under strict labor and environmental regulations. A green check mark indicates a brand meets our responsible manufacturing criteria, while a red X means it does not.
Recycled and/or Reduced Packaging
Packaging can add significant waste to outdoor gear purchases, so many brands work to reduce its impact by using recycled materials, incorporating Forest Stewardship Council-certified paper products, and minimizing plastic and paper use. A green check mark indicates a brand uses recycled or reduced materials across all of its packaging, a yellow check indicates moderate or limited use of recycled or reduced packaging, and a red X indicates the brand does not make either of these efforts.
Repair Services
Repair services extend the lifespan of outdoor gear and reduce overall consumption, though programs vary widely. Some brands offer comprehensive repairs for a range of issues, while others provide limited or no repair support. A green check mark indicates a robust repair program, a yellow check mark indicates limited repair services, and a red X indicates the brand does not offer repair services.
Resale and/or Recycling Services
Resale and recycling programs help keep outdoor gear in circulation longer and out of landfills, ranging from trade-in resale platforms that offer store credit to take-back initiatives that recycle products at the end of their usable life. A green check mark indicates a brand offers both resale and recycling programs, a yellow check mark indicates it offers one or the two, and a red X indicates it offers neither.
Carbon Footprint Tracking
This criterion evaluates whether a brand measures, reports, and works to reduce its greenhouse gas emissions using established frameworks such as the Higg Index, Greenhouse Gas Protocol, or The Change Climate Project. A green check mark indicates a brand publicly reports greenhouse gas emissions data, sets clearly defined reduction targets, and uses established tracking frameworks such as Higg or The Change Climate Project. A yellow check mark indicates the brand tracks emissions and outlines reduction goals but provides limited data, lacks science-based verification, or does not clearly report progress. A red X indicates the brand does not appear to track greenhouse gas emissions or provides so little information that its efforts cannot be verified.
Annual Impact Report
Annual impact reports provide transparency and accountability by outlining a brand’s sustainability efforts across areas such as material sourcing, greenhouse gas emissions, waste, water use, supply chains, and packaging. A green check mark indicates a brand publishes a detailed, brand-specific impact report that closely aligns with our sustainability criteria and leaves little room for ambiguity. A yellow check indicates a brand provides some relevant sustainability reporting but lacks detail in key areas or is covered only briefly within a parent company report. A red X indicates a brand does not regularly publish an impact report.
Size tested: Medium torso, extra-large hipbelt
Zpacks’ sizing options for the standard Arc Haul UltraEXP include two torso lengths—short (16-19 in.) and medium (19-23 in.)—and four hipbelt circumferences ranging from small to extra large. With a 20-inch torso, I chose the unisex side medium length with an extra-large hipbelt. While the hipbelt size served me well, during testing, I felt that the pack was a bit too long, and I probably could’ve gone with the small torso length instead. However, the torso length is adjustable via a (slightly complicated) strap system, so I was able to set it to its shortest possible length.
The Arc Haul UltraEPX also comes in a women’s version, which features women’s-specific shoulder straps and is available only in the short torso length. Zpacks also recommends this version for teenagers. Like the standard version reviewed here, it offers a full range of hipbelt sizes.
Hyperlite Southwest 55 ($420): More Capable, Still UL
Along with the Arc Haul UltraEPX, the Hyperlite Mountain Gear Southwest 55 is among the ultralight backpacking pack category’s most elite. At just under 2 pounds, it’s a little heavier than the Arc Haul UltraEXP (which puts in perspective just how dang light the Arc Haul is), and its two aluminum stays allowed us to comfortably carry 35 pounds, in line with the Arc Haul’s rating. Where the Southwest stands out is its proven durability: The Southwest is a pack for bashing through bushwhacks, and has the track record to support it, whereas the Ultra fabric on the Zpacks is still relatively new, and we have concerns about its mesh and stitching. But on the other hand, the Arc Haul’s raised mesh backpanel offers far more breathability than the Southwest’s Dyneema Woven Composite fabric design. For more, read our review of the Hyperlite Southwest 55.
Gossamer Gear Mariposa 60 ($315): For Feature Lovers
The Gossamer Gear Mariposa 60 is also heavier (2 lb. 2.2 oz.) than the Arc Haul UltraEXP, but that shouldn’t come as a surprise at this point. Unlike the Hyperlite Southwest, the Mariposa’s extra ounces aren’t a result of increased durability, but rather a more robust feature set. Like the Zpacks, it has two side pockets and a mesh dorsal pocket, and tacks on an adjustable top lid with a small pocket and two large zippered pockets on each hip. What’s more, its removable foam backpanel doubles as a sit pad. Gossamer Gear rates the Mariposa at 30 pounds “for comfort,” with a max of 35 pounds. A price tag of $85 less than the Arc Haul is a point in the Mariposa’s favor, but its 100-denier and 210-denier Robic nylon also needs to be treated with care. For more, read our review of the Gossamer Gear Mariposa 60.
This 1-pound, 7-ounce pack isn’t just light: Its suspension allowed us to carry up to 30 pounds comfortably, and its trampoline-style backpanel promotes airflow. Drawbacks include a somewhat unrefined look, lack of pockets, and—yikes!—that price.
Comfort
Organization
Weight
Durability
Water Resistance
Sustainability
Load capacity, durability, and waterproofing make the Southwest a thru-hiker favorite. Drawbacks include a lack of adjustability and below-average padding, but in most other aspects, this is a top-tier ultralight backpack.
Comfort
Organization
Weight
Durability
Water Resistance
Sustainability
This ultralight pack is right up there with the category’s elite in terms of carrying capacity and organization, and it features better padding than most. The Mariposa isn’t super durable, though, and we had a sample issue with its hipbelt during our CDT thru-hike.
Comfort
Organization
Weight
Durability
Water Resistance
Sustainability
Is the Arc Haul UltraEPX 60L for You?
Sussing out caveats is part of the gear-testing process, and the Zpacks Arc Haul UltraEPX 60L comes with its fair share. While this is a wonderful pack for true ultralighters—backpackers who can grab and go with a kit that’s trail-tested for minimum weight and maximum efficiency—it’s not ideal for traditional backpackers who value comfort, convenience, and durability. The fabric is thinner than competitors', the storage layout requires thoughtful packing, and comfort dips above about 30 pounds. But if you’ve pared down your base weight and are in the rare group of hikers who think a pack like the Hyperlite Southwest is too heavy, the Arc Haul could be for you. It’s impressively lightweight and still offers decent comfort, great breathability (rare in the ultralight space), and full-on waterproofing.
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