Brave the Elements in These Burly Bottom Layers: Black Diamond Alpine Pants Review

We woke up in the dark, rubbing the sleep out of our eyes, anxiously anticipating our summit push. The slight chill in the air would mean better snow travel conditions for our ascent, so we dragged ourselves out of our cozy sleeping bags and fired up our stove for instant coffee. Alpine starts are always rough at first, but we were soon rewarded by streaks of purple, red, and orange light forming over the peaks. 

Despite the early morning chill, I knew that as soon as the sun hit the snow, we would be in a solar oven. Layering for summer mountaineering objectives can be tricky; I needed some weather resistance but not too much insulation. I was glad that I packed the Black Diamond Alpine Pants for this midsummer climb of Eldorado Peak in the North Cascades.

As a year-round rock and alpine climbing guide, climbing pants are part of my daily uniform. The more time I spend working in the mountains, the more particular I’ve become about clothing; small details in fit and design can affect my ability to do my job.

Differences in durability become apparent after working season after season in the alpine and the desert, and I’m willing to spend a bit more for gear that lasts. BD’s Alpine pants have earned their place in my kit.

In short: For those venturing deep into the mountains or climbing on cool, windy days, the Black Diamond Alpine Pants are a solid choice. The fabric has a durable water-resistant (DWR) finish that protects it from wind and light precipitation, and the design includes key technical features like zip pockets, ankle drawcords, and articulated knees. With a slightly different cut, the men’s version is equally an equally mountain-capable pair of mountain trousers.

If you’re shopping for climbing pants, see how BD Alpine pants stack up to the competition in GearJunkie’s guide to the Best Women’s Climbing Pants and the Best Men’s Climbing Pants.

Black Diamond Alpine Pants Review

I recently guided a 4-day mountaineering course to Eldorado Peak in the North Cascades, and I packed the BD Alpine Pants as my primary pant layer. This trip involves a steep approach through the forest, scrambling through a boulder field, slogging up snow slopes, and moderate glacier travel to an iconic summit.

I’ve also taken these pants on several single-day alpine rock climbs in the Cascades. After a season of use, I’ve found them to be a capable pair of softshell pants, complete with all of the major design features I require.

Weather Resistance

Soft-shell pants are my go-to bottom layer for mountaineering and alpine climbing missions. One major difference between softshells and cragging pants like the Patagonia Caliza Rock Pant is weather-resistant fabric. Mountain forecasts can change unexpectedly, so it’s important to be prepared for a range of conditions. Look for a DWR finish that will shed precip and cut the wind. 

While staying at the Eldorado Peak high camp, we experienced some surprisingly blustery weather one evening, despite the forecast calling for calm. The fabric of the Alpine Pants easily cut the wind and retained warmth; I didn’t even need to add base layers.

Usually, when a pair of pants adds weather resistance, they lose some degree of breathability. Sure enough, my legs quickly got hot as we descended to lower elevations, and I was glad I brought shorts. 

Despite the heat, I still think these pants were perfect for my trip to Eldorado Peak. They’re not as heavy as other softshells, like the women’s Incline Pants made by Rab, which are great for spring mountaineering.

I can always layer long underwear with the Black Diamond Alpine Pants for colder weather, and I usually bring a light pair of shorts for hot approaches in the Cascades. If there are storms in the forecast, I would pack a pair of hardshell pants, too, because the Alpine Pants are not fully waterproof. 

The Alpine Pants are also constructed with a PFC-free DWR finish, which means they do not contain perfluorochemicals or PFCs. PFCs are synthetic compounds, sometimes known as “forever chemicals,” that persist in the environment and can accumulate in nature and in the human body. Studies have associated PFCs with adverse birth outcomes when they are detected in pregnant women. Black Diamond is moving away from these chemicals to contribute to long-term human and ecosystem health. 

Technical Features

Smart features on technical clothing add efficiency and ease to a long day of climbing in the mountains. For me, a thigh zip pocket that is big enough to easily fit a smartphone is a mandatory feature.

I use my phone regularly for navigation, and I’m always trying to take good photos to share with my clients or other guides. I can easily slide my phone into the zippered thigh pocket of these pants, and the two front zippered pockets are nice for stashing other key items like SPF chapstick.

Another important feature is the strong and secure ankle drawcord. If the snowpack is consolidated enough that I decide not to bring gaiters, I can tighten the ankle drawcords around my boots to keep out snow.

If I’m wearing crampons and have extra webbing from the straps, I like to stuff it into the bottom of my pants to keep it from becoming a tripping hazard. This method only works if the draw cord is quite tight. If I’m rock climbing, I also use this feature to keep my pants out of the way of my feet, so I can focus on solid footwork. 

A Few Gripes

In my opinion, one design flaw of the Alpine Pants is the bulky buckle at the waist belt. Not only is this large plastic buckle slightly uncomfortable under a harness, but it also seems like something that could easily crack. Luckily, Black Diamond soft goods come with a warranty for the lifetime of the product, but I think a low-profile, metal buckle would work better.

I’m also curious to see how durable the zippers are with future testing. I owned a pair of the Black Diamond Alpine Light Pants in the past, and I found that the pocket zippers broke quite quickly.

Fit and Mobility

When I’m wearing a harness, I want my pants to sit above the waistbelt of the harness so they don’t get in the way. I like the high-waisted fit of the BD Alpine Pants and found them to be pretty low-profile under a backpack or harness.

The legs were pretty long on me, which I’m used to as a 5’2” climber, but unfortunately, Black Diamond doesn’t offer different inseam lengths in this style. There are also no plus-size options. 

GearJunkie editor Matt Bento tested the men’s cut of these pants and reports that at 5′ 10″, he found the length was perfect for him, though the thighs could feel a little tight on a guy with bigger mountain legs.

The four-way double-weave stretch fabric makes climbing movement a breeze, and the articulated knees add to the impressive range of motion. I never felt constricted while high-stepping or stemming, which is mandatory in climbing pants for me. The only slight discomfort came from the bulky buckle that I mentioned above; I could feel it pinching a bit during some particularly high steps.

Who Are These Pants For?

For long days in variable conditions, the Black Diamond Alpine Pants are a great choice. If you’re planning a warm-weather cragging trip, I would look for something lighter and more breathable, like the Mountain Hardwear Dynama II Ankle Pants or the Patagonia Caliza Rock Pants found in our gear guide. Black Diamond also makes an Alpine Light Pant constructed with lighter fabric while still offering a DWR finish. 

Reach for the Black Diamond Alpine Pants when you need a little extra weather protection early in the alpine rock or mountaineering season. Add some wool base layers, and they could even carry you all the way into winter ice climbing season.