There are men who push the limits of what is possible. Climbers who endlessly explore the most vertical faces of the Alps. Gilles Sierro is one of them. Mountain guide, ski instructor and steep-slope virtuoso, this gliding enthusiast has made the Alps his high-altitude kingdom. Known in particular for his spectacular descents from the Dent Blanche, Gilles today opens the doors to his world, where rigor and freedom combine harmoniously. He reveals with sincerity what drives him, from his quest for serenity at altitude to the joy of passing on his passion. He tells us about his fondest memories, his relationship with risk, his encounters with animals during his photographic escapades and, above all, his unique relationship with the mountains. Meet Gilles Sierro, the man who dances with the slopes of the impossible and the lover of the Dent Blanche.
Gilles Sierro: mountain guide and summit lover
Hello, Gilles. You're a mountain guide, ski instructor and steep skier. Can you tell us more about your background?
I started skiing at the age of two and a half. The sport came to me quite naturally, as my father was a ski teacher and we lived in the resort of Hérémence. I competed in downhill skiing until I was 16, especially in giant slalom, as many young mountain people do. I then qualified as a ski instructor in Switzerland, and went straight on to train as a guide. By the age of 30, I was a guide and a teacher.
People call you "Gilles the skier". The mountains play a central role in your life. How do you feel when you're up in the mountains?
The way I feel in the mountains varies according to the circumstances. When I'm guiding clients, my main focus is on realizing their dreams and achieving their goals. I'm more focused on their experience than my own. On the other hand, when I'm on my own, I search above all a form of mental quietude. The mountains offer me an escape from the hustle and bustle of everyday life. Bills, problems, all those little worries vanish. Skiing down a steep slope, only the present moment counts, everything else disappears. The experience brings a calmer, more collected state of mind.
What values do you believe high mountains embody?
For me, the high mountains represent several essential values. First of all, rigor is essential. On a steep slope, at a high level, without this rigor, you won't go far, or for long. Yet this rigor coexists perfectly with friendship and moments of relaxation. When I think back to descents with Vivian Bruchez, it's our laughter and complicity that come back to me first. That's the atmosphere I remember. For me, the high mountains embody the combination of friendship, rigour and the pleasure of simple things: contemplating a sunrise, appreciating the quality of the snow, savouring a cup of hot tea.... Things don't have to be complicated to be beautiful. In our daily lives, we are often caught up in complex patterns where everything has to be perfect, in the right place, at the right time. At altitude, the opposite is true: simplicity is enough to make everything perfect.
La Dent Blanche : the perfect mountain as seen by Gilles Sierro
You're best known for your spectacular descents from the Dent Blanche. What does this exceptional mountain mean to you?
For me, it's the perfect mountain, the one we instinctively draw as children: a triangle with a little snow at the summit. It's THE emblematic mountain of our valley, next to the Matterhorn. If the Matterhorn is king, then the Dent Blanche is queen. It's often said of me that I was the Dent Blanche's lover, and she my mistress. That's not entirely untrue. Above all, it's the first truly great mountain I've ever seen in my life, and one that I observed on a daily basis. It's the 4000 of our valley.
Of all your adventures on the Dent Blanche, which memory has left the deepest impression on you?
If I had to choose just one memory, spontaneously, it would be my first on the north face of the Dent Blanche Blanche in June 2024. It was the fourth face of the Dent Blanche Blanche that I had skied down. I see this last descent as the end of a cycle. The end of my obsession with this mountain. Every time I accompanied clients to the summit the Dent Blanche, I would examine the slope and imagine possible trajectories. The descent I made on the north face had an incline of over 50 degrees for its entire length. At the steepest point, I was approaching 58 degrees. It was particularly impressive, all the more so as the snow was sparse. Below us lay a rocky bar some 300 metres long. That day, there was between 5 and 20 centimetres of snow on ice and rock. I even had to brace myself on an ice pin to get my skis on, as the surface was so slippery. The line is clearly visible in a photograph captured by Thomas Crauwels. It was absolutely incredible, just perfect! Skiing there was like being on a springboard suspended above the void. It was breathtakingly beautiful.
Gilles Sierro and the art of passing on his passion
Let's talk about your job as a mountain guide and ski instructor. How important is transmission to you?
I think we experience so many beautiful things in the mountains that we naturally feel the urge to share them with others. When you're skiing, you experience unique sensations, discovering landscapes you'd never be able to see from down below. You also experience deep inner emotions. For me, that's the real motivation behind transmission: to enable my customers to experience these powerful emotions. And then there's friendship too. In the mountains, when you do three or four races with someone, you become friends for years. The mountains are a bit like watching life in fast-forward: you experience everything more intensely.
Your job is not without risks. Has your relationship with the mountains changed since you became a father? Do you want to pass on your passion to your children?
My relationship with the mountains has evolved, but more in the way I talk to my children about them. I try to focus on the beauty, rather than on what's dangerous or sad. They're five and three, so I prefer them to have a still-romantic image of the mountains, one that makes them want to go there. It may sound strange to say, but I don't feel that I took excessive risks before I had my children, and I continue to operate in the same way. I've always done everything to limit the risks and eliminate the dangers as much as possible. Of course, the mountains are a passion that I'd like to pass on to them. I think that, given where we live, it's part of our identity. The mountains can transmit some very fine values, even if they can sometimes be tough. I'd like to teach them to love nature, the simple fact of being outdoors, whether in the forest or in the mountains. When it comes to skiing, they're already completely hooked. And like many children, they want to follow in their daddy's footsteps and become guides!
Gilles Sierro: amateur wildlife photographer
You're also a wildlife photographer. Can you tell us about your most beautiful animal encounters?
I'm not at the level of Thomas CrauwelsI'm more of an amateur photographer. Among the memorable encounters I've had, two in particular stand out. The first was a herd of deer at sunrise, during the bellowing season. I was taking photos on a backlit ridge, and suddenly a sunlit cloud came up just behind them, creating a totally unreal scene. It was a perfect moment, with incredible colors that I didn't even need to retouch. This photo really made an impression on me.
The second memory also concerns a deer, the most imposing in our valley, a veritable colossus that I was lucky enough to follow for five years. The first time I saw him was extraordinary. I stayed with him for three and a half hours, hidden just 35 meters away, without him noticing me once. I took over 500 photos until I didn't know what to do with them, then discreetly left without him seeing me. In the years that followed, I was happy to see him again every season, until 2025, when I saw him one last time in a reserve. Two days later, he was shot while hunting. He was at the end of his best season, no longer the king he had once been. I had mixed emotions: it was sad because I wouldn't be seeing him again, but I knew he'd gone at the right time, before his decline. The gamekeeper, who knew my history with this animal well, gave me the opportunity to see it one last time. It was very special and moving. It's a story full of contrasts, with ups and downs, but deeply moving.
Gilles Sierro: helping to shed light on the grandeur of the Alps
How would you say your activities help to highlight the greatness of the Alps?
I believe that my activity as a steep ski guide enables me to take people to places they would never have gone to otherwise. By helping them discover these extraordinary places, we turn them into ambassadors for the mountains. When my customers come back down, they talk about what they've experienced, how beautiful it was, and this naturally makes them want to protect these areas. What's more, thanks to the steep slope, we can highlight summits that are usually less well-known for skiing, such as the Grandes Jorasses, the Bietschhorn, or even the Dent Blanche. These are primarily mountaineering summits , but by approaching them from a different angle, we also help to showcase them in a different way.
Gilles, thank you for your kind words. Would you like to add anything to end our discussion?
Yes, I'd like to take this opportunity to say thank you to Thomas Crauwels. Since the descent of the Bietschhorn in 2021, all the photos of my first descents have come from him. He allowed me to draw my lines directly on his photographs. It's a great way to collaborate.
Through vertiginous slopes and conquered summits , Gilles Sierro embodies the soul of the Alps at its purest. His passionate gaze reminds us that the mountains bring us back to the essential: the beauty of a moment, the strength of a friendship, the simplicity of a moment lived to the full.
