Picking gear for a thru-hike is a daunting and difficult decision. We decide what is and isn’t necessary. We dial down our kit to save weight and costs in the places we can, but there are a few items it’s never recommended to make serious compromises on — tents, sleeping systems, and backpacks. 

The majority of a thru-hike is spent wearing your pack, so you’ll want something comfortable that fits your hiking style and the changing environments. Transitioning from long desert water carries to cold, snowy alpine zones, hikers need the right bag to swap gear in and out of, as well as durability during the changing conditions of a multi-month trek.

Many thru-hikers have consistently chosen ULA packs on long trails for years for these reasons. The newly released (and greatly updated) ULA Equipment Ultra Circuit isn’t the tiny ultralight fastpacking mini bag you may prefer on your FKT attempt; however, it’s a bag for the rest of us, carefully designed for big trails, a big lifetime, and big smiles.

In short: The ULA Ultra Circuit comfortably carries loads and lasts a long time. Recently updated with durable ULTRA fabrics, this thoughtfully designed bag is a great option for both the adventurer new to the trail life and the intrepid grizzled hikers looking for an expedition-style pack to meet their needs along an entire trail.

ULA Equipment Ultra Circuit Backpack: Review

I first used a ULA pack on the PCT in 2018 when I needed to get a lighter and better-fitting pack for the Sierra. I ordered a ULA CDT, which is smaller than the Circuit, and it lasted me the rest of the trail and a couple of years afterward.

I’ve used a variety of packs on my thru-hikes and backpacking trips over the years, all between 30 and 75 L. After covering over 7,000 miles backpacking in the U.S., I found many things I both love and dislike about the backpacks on the market and refined my taste for specific gear for each mission I embark on. 

I took the ULA Ultra Circuit out for its initial voyage on an overnight canyoneering trip in Grand Canyon National Park. My partner and I loaded up all of our camping gear, all relatively ultralight, along with all of the technical equipment for the canyon descent, including hundreds of feet of rope, carabiners and other hardware, a sizeable amount of anchor-building material, harnesses, and food for two days.

We drove out to the north rim of Grand Canyon and spent the night camped on the rim. We woke up the next morning well before sunrise to hike and canyoneer down to the river and hike back to camp. 

It’s safe to say that the Ultra Circuit performed very well hiking with the heavy pack around 8 miles across the rim, bushwacking, and scrambling through cacti fields and thick brush. We finally made it to the mouth of the canyon, where we donned our gear and rappelled into the crack in the earth.

Grand Canyon limestone is sharp, and the sandstone is abrasive. After a full day of sliding, scraping, and thrashing the bag through the canyon, the only real damage was a small hole in the outside mesh pocket and a single missing bottom strap.

I was honestly surprised by how well the ULTRA fabric held up, considering the bag wasn’t designed to withstand this particular experience. This only inspires more confidence in the tear-resistant material.

Over the arduous miles and thousands of feet of descent, boulder hopping, and then thousands of feet of ascent back out of the Grand Canyon, the pack was never uncomfortable. The adjustable hip belt felt secure all day, and the shoulder straps never bothered me.

Choosing the correct size of bag and components is necessary, which ULA makes easy on its ordering page. I took the time to measure my back and waist and made sure the shoulder strap design was the right one for me, and it sure paid off during that trip.

Later, I took the pack to the Tushar Mountains in Utah for a trip with lots of elevation gain and a heavy load. This time, rather than loading up with canyoneering gear, I brought my big camera and tripod to shoot video and photos of the hiking trip.

Hiking between 9,000 and 12,000 feet, I hiked a loop adjacent to the Tushar High Route, covering around 25 miles over two days. I was impressed with how comfortable the carry was after topping out on several peaks covered in snow and wildflowers. Not loaded up with nearly as much weight as the previous excursion, my bag was still relatively heavy with the extra equipment and sleeping kit.

Aside from these two different trips, I’ve taken the pack on a few day hikes around Zion National Park to play with features and see how it feels to use in the field. I love plenty of things about the Ultra Circuit, but there are a few things I don’t. Let’s break down the things that stood out to me about the pack.

What It’s Really Made Of: ULTRA and UltraStretch Mesh

ULA has decided to use the ULTRA fabric made by Challenge Sailcloth for its line of bags. The pack uses both ULTRA 400x and 200X Ultra-High Molecular Weight Poly Ethylene fabric finished with 0.5-mil RPET Film — making it waterproof and seam tapeable (though, unfortunately, the bag is not seam taped).

It’s also highly abrasion-resistant, has high tear strength, and is UV damage-resistant. All around, it’s good stuff for a backpack that meets all sorts of tough environments and conditions in the wilderness.

The bag surprised me by how well it held up in the Grand Canyon, scraping through sharp limestone and clawed plants. The only thing damaged during the canyon descent was the UltraStretch Mesh fabric on the outer pouch.

Another big positive of the backpack is the range of sizing options for the components when you order a ULA pack. Torso length options range from small to XL, and the hip belt ranges from XS to XXL, along with the J and S straps, making it easy to personalize the backpack for each person’s body shape.

This pack fits me so well in comparison to other bags I’ve used of similar size and price range. Considering how much money hikers are spending on gear these days, purchasing a pack that actually fits is a huge deal. ULA’s website has great instructions and a size chart to help you correctly choose the right size Circuit.

Things That Just Make Sense About the Ultra Circuit

Some of the small things that make a big difference for me are the large hip belt pockets — this is a huge user experience boost for a backpack’s usability. Packing those puppies full of what I’ll want or need regularly throughout the day without having to take off or unpack my backpack is necessary. The zippers on the hip pockets are waterproof — it just makes sense. 

The top compression strap comes in two variations, the single strap or the Y strap, which is great for attaching larger items like a bear canister or your new flavor of chips to pack out from town. The pack is also big enough to fit said bear canister inside the pack, vertically for larger cans and horizontally for some smaller-sized canisters, freeing up the top for even larger salty snack bags.

It seems like it’s the standard these days, but having two ice axe/trekking pole loops on the pack wasn’t the norm for every bag back in the day. Adding these ice axe loops is a great update for the ULA Ultra Circuit and a necessity for many thru-hikers on long trails trekking in the early-season snow.

ULA’s “four-point-contact hip belt system” makes the hip belt uber adjustable, something I thought I wasn’t going to like at first, but have come to appreciate the level of comfort this added to the system.

What Could Be Better

Only a few design choices on the Ultra Circuit stood out to me in a negative way. The bag isn’t seam-taped, so it isn’t completely waterproof. This is despite being made with water-resistant fabric, a roll-top closure, and waterproof zippers. Hikers will still need to use a bag liner to prevent equipment from getting wet.

The other feature I disliked was that the optional top and bottom straps connected with a “G hook,” which is only a partially secure connection point. While the chance of the straps coming off on their own accord is low, environments with more snagging potential could accidentally remove these buckles from the pack.

One of my bottom straps became detached during a down climb on one of my backpacking trips. Some kind of snapping or locking connection would be a great update for this pack in the future for hikers and backpackers who are taking this durable bag into more rugged, gnarly terrain and environments. 

It may be a little nit-picky to mention this other issue. When stuffed with larger 1.5L bottles, or two bottles together, the water bottle pockets are slightly less than easy to use. Compared to other styles of side pockets competitors’ designs, these are stiff and made of the same ULTRA material, but not as stretchy where they cinch down around the bottle.

Because of the way this backpack was designed, the bottom of the bag is curved, and it doesn’t sit upright on its own. While this forces you to pack your bag with weight more evenly distributed inside, trying to get it to stay right side up while packing up camp in the morning became frustrating.

Lastly, I would love it if the UltraStretch Mesh dorsal pocket in the back was just a little bigger. It feels a bit small and hard to sift around in when I have a few items and a jacket jammed into it. While it keeps the pack profile sleeker and less easy to snag, I’d love to see a pocket that makes it easier to get items in and out of. 

Is the ULA Ultra Circuit Worth the Hype?

The ULA Ultra Circuit is a fantastic back for thru-hikers on trails like the PCT or CDT, where hikers will encounter long carries, traverse a wide variety of terrain and trail conditions, and want a pack to last that does almost everything.

There is enough room in this 40L internal pack to fit the necessities for a three-season thru-hike, and the bells and whistles on the outside are just right, with no unnecessary components included. There’s a reason the Circuit is one of the most popular packs on the Pacific Crest and Continental Divide trails. We want the trusty durability and comfort of a pack like this. 

You may think that this isn’t the pack for you — it won’t be the perfect bag for everyone. Coming in between $397 and $414, it certainly won’t be in everyone’s price range. There are cheaper and lighter packs on the market for Ultralighters, but not all of them have the same load-carrying capacity for those long sections of roadless backcountry.

For hiking in bear canister territory, long food/water carries, wet conditions, and rugged terrain, this is a great backpack for the all-summer thru-hike or shoulder-season traveler.

Thru-hikers looking for a customized lightweight backpack that will last for more than one thru-hike carrying all your gear and food across deserts and mountain ranges all summer long, this is the bag for you.

ULA Ultra Circuit Pack: Conclusion

ULA Equipment has found a great place in the middle for its ultralight backpacks compared to competitors. The Ultra Circuit pack might be a little heavier than some of the other packs with similar volume, but the load capacity is better. In the same vein, some packs carry slightly heavier loads, like the Hyperlight Southwest, but the ULA one-ups them in adjustability without compromising the weight of the backpack itself.

So, no, it won’t be the pack you’ll saddle up in for your calendar year Triple Crown. But is the Ultra version of the pack worth the added $80 needed to trim it out in super-durable ULTRA fabric? That’ll depend on your planned usage.

Well-worn trail? Go with the regular Circuit. But a thru-hike of the Hayduke Trail? Best to grab the Ultra version. That added thick skin will be paying out dividends for miles to come.