Name: Arc'teryx Gamma SL
Brand: Arc'teryx

The Arc’teryx Gamma SL earns top marks for its exceptional comfort and freedom of movement. The fabric blend—nylon with 14% elastane and a soft knit mesh liner—offers a smooth, stretchy feel that moves fluidly with the body while retaining just enough structure to stay supportive. Articulated patterning and a gusseted crotch further enhance mobility, and Arc’teryx’s refined fit helps the pants stay securely in place without feeling restrictive. All told, the Gamma SL is one of the least restrictive hiking pants we’ve worn, making it an excellent choice for everything from trail hiking and travel to scrambling and alpine climbing.

One Better Trail editor has long relied on the Gamma SL for alpine rock climbing, citing its ability to accommodate high foot jams, long days on the wall, and the occasional alpine knee. She also calls out the built-in waistbelt as a major comfort win, keeping the pants firmly in place under a harness or hipbelt. The Gamma SL does stretch out slightly between washes, which is fairly standard for pants in this category. That said, compared to the Outdoor Research Ferrosi, the Gamma SL is just as soft and stretchy but offers a more structured, durable feel that holds its shape and performance better over time.

Jumping between rocks in the Arc'teryx Gamma SL hiking pants

The Gamma SL is built to last, with a tough softshell nylon face fabric and the meticulous construction we’ve come to expect from Arc’teryx. Abrasion resistance is excellent, and unlike the Outdoor Research Ferrosi, the fabric doesn’t pill or show too many signs of wear (read our Ferrosi review). We’ve relied on the Gamma SL as a go-to climbing pant for everything from multi-pitch granite to sharp alpine routes, and it’s held up impressively well through seasons of heavy use.

That said, no pant is indestructible. One of our well-worn pairs has developed a few small holes, but they haven’t spread and are easy to patch with repair tape. The main weak point is the fabric on the thigh pocket, which wore thin from the pressure points caused by carrying a phone while climbing. This is a common issue in climbing pants, but one we’d love to see Arc’teryx address with a reinforced overlay in future iterations (for now, our Tenatious Tape reinforcement will do). Still, overall durability is among the best in class for such a lightweight softshell design.

The Gamma SL is about as lightweight as a softshell pant gets—significantly lighter than the standard Gamma—but it still feels more structured and substantial than truly minimalist options like the REI Co-op Trailmade. It’s well-suited for summer missions in the mountains, but in temps above 70°F, it can start to feel a bit too warm. On hotter approaches, we often hike in shorts and change into the Gamma SL at the base of a climb. For a thinner alternative, the Black Diamond Alpine Light Pant sheds the knit liner and feels more air-permeable overall.

That said, the Gamma SL’s knit liner is the reason it breathes as well as it does. It wicks moisture efficiently and prevents that sticky, plasticky sensation many synthetics develop with sweat. While we prefer the BD Alpine Light for warm days on the wall, the Gamma SL is the better hiking pant overall—its roomier fit promotes airflow, and the liner keeps things drier and more comfortable during high-output movement (read our Alpine Light review).

Hiking in evening light in the Arc'teryx Gamma SL hiking pants

The Gamma SL’s softshell construction offers impressive protection for a lightweight hiking pant. The tightly woven fabric blocks wind far better than standard nylon options like the Patagonia Quandary, making it a strong pick for shoulder-season use or exposed, high-alpine terrain. The DWR finish is also a top performer, shedding light rain, mist, and even damp brush with ease.

Of course, these aren’t full-on rain pants. In steady precipitation, we found the fabric begins to wet out after about 15 minutes. On the bright side, it dries quickly and remains comfortable when damp, making the Gamma SL a reliable choice for variable conditions and multi-day missions where fast drying is key.

Pockets
The Arc’teryx Gamma SL keeps it simple with three zippered pockets: two hand pockets and one on the thigh. While the absence of rear storage might be a downside for casual, everyday use, it’s a non-issue in the backcountry. All three pockets are zippered, which we appreciate for securely stashing a phone, lip balm, or Sour Patch Kids without worrying about items slipping out mid-hike or during a trailside break.

That said, our one recurring gripe—common across many climbing pants—is the durability of the thigh pocket. Stashing a phone there while climbing leads to repeated abrasion against rock, and over time, we’ve worn small holes into the fabric. It’s an easy fix with Tenacious Tape, but we’d love to see Arc’teryx reinforce this high-wear area in future versions. For now, the thoughtful pocket layout and zippered security make the Gamma SL a practical and low-fuss choice for technical missions.

Thigh pocket on the Arc'teryx Gamma SL hiking pants

Waistband, Cuffs, & Other Features
The Gamma SL keeps things streamlined with a minimalist feature set, but what’s included is well executed. The built-in belt is a standout: the women’s version we tested features a low-profile cinch on the right hip, while the men’s uses a more traditional metal hook and webbing loop. Both designs provide a secure, dialed fit and are especially appreciated given that the pants stretch slightly between washes. It’s a huge boon to be able to easily tighten the waist throughout a trip to ensure they continue to ride comfortably and stay put under a pack or harness.

One feature we wish Arc’teryx hadn’t skipped is adjustable hem cinches. Without them, we have to roll up the cuffs to keep the pants off our feet when wearing climbing shoes or sandals. To their credit, Arc’teryx did add grommets at each hem, allowing you to thread cord through and secure the cuffs under your boots or approach shoes for a gaiter-like effect.

Built-in belt of the Arc'teryx Gamma SL hiking pants

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Longevity

Choosing durable outdoor gear is perhaps the most effective way to reduce environmental impact—the longer it lasts, the less it needs to be produced. Our proprietary longevity rating evaluates overall build quality based on factors such as materials, fabric denier, component durability (including zippers and toggles), real-world performance as reported by our field testers, and our experiences with the brand.

Read Sustainability Report

Tester: 5’3” 103 lb., 25” inseam; 26.5” waist
Size tested: 00 Short

Arc’teryx consistently nails the fit, and the Gamma SL is no exception. The women’s version features a flattering, fitted silhouette that contours without feeling restrictive, while the men’s version has a roomier, regular cut. Both come in an impressive range of sizes and three inseam lengths, boosting your chances of finding that just-right fit. One tester described the pants as having a “trouser-like look”—trim but not tight, and far from sloppy. Thanks to the built-in belt, the mid-rise waist sits comfortably and stays put whether you’re hiking, scrambling, or lounging at camp. All in all, it’s one of the best-fitting hiking pants we’ve tested: streamlined and mobility-ready, with enough polish to look good around town too.

Arc’teryx Gamma ($200): Warm it Up
The Gamma Pant is the burlier sibling to the Gamma SL, with a thicker, heavier fabric that offers more warmth for shoulder-season use or cooler climates. The pants share the same high-end construction, fit, and feature set, although the standard Gamma tacks on cinchable hems at the cuffs—a useful addition for sealing out debris or tightening over climbing shoes. If you’re venturing into cooler conditions or need a more rugged softshell for mixed terrain, the Gamma delivers. But for most hiking applications, we think the lighter SL offers better versatility and all-day comfort. For a deeper dive, read our Arc'teryx Gamma Pant review.

Outdoor Research Ferrosi ($99): Easier on your Wallet
If you’re shopping in the lightweight softshell category, the Ferrosi is a solid alternative that comes in at a much lower price. Its fabric offers similar stretch and weight to the Gamma SL, but the durability trade-offs are clear: the Ferrosi tends to pill, shows wear more quickly, and its DWR finish wears off noticeably faster. It’s also less structured, which makes it more susceptible to snagging on rock. The Gamma SL, on the other hand, retains its shape better over time, wicks moisture more reliably, and looks far fresher after a season of hard use. The addition of zippered hand pockets is another key advantage, especially for securing essentials on the trail. We think the Gamma SL is worth the extra $60 for its longevity and polish, but the Ferrosi remains a supremely comfortable, capable pick for more casual or cost-conscious users. For more, read our review of the OR Ferrosi.

Arc'teryx Gamma SL ($160)

Hands in pockets of the Arc'teryx Gamma SL hiking pants

4.6/5

The lightest pant in the Gamma series, the SL blends the stretchy, weather-resistant performance of a softshell with a streamlined build tuned for mild mountain conditions. It’s an excellent choice for high-alpine travel in summer, but can feel overkill for warm, below-treeline outings.

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Is the Gamma SL for You?

The Arc'teryx Gamma SL is a top choice for hikers, climbers, and other mountain-goers who need a lightweight softshell hiking pant that won’t hold them back. With its stretchy construction, impressive weather resistance, and abrasion-ready durability, it’s built for unrestricted movement and reliable protection on alpine missions—whether you’re scrambling, climbing, or navigating variable terrain. Some may find its lined construction a bit warm for approaches, but the SL remains impressively versatile across a range of conditions. Its clean, refined fit also pairs well with everyday layers without looking overly technical, adding to its off-trail appeal. Budget-conscious shoppers may hesitate, but it’s hard to beat this level of performance and longevity for the price.