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Distance

104KM

Elevation

6,500M

Start Date

Sat, 16th May 2026

Location

Llanberis

Cut-off Time

32 Hours

Ultra-Trail Snowdonia 100K (UTS 100K) by UTMB

Conquer the heart of Eryri/Snowdonia National Park with the Ultra-Trail Snowdonia 100K (UTS 100K) by UTMB, a formidable challenge that distils the rugged beauty and extreme demands of this iconic mountain range into a 100-kilometer test of endurance. This ultra marathon is a true showcase of technical mountain running, offering a shorter yet equally savage experience compared to its 100M counterpart.

The Course

The UTS 100K is crafted to push participants to their limits, guiding them over many of Snowdonia's trickiest summits and most technical ridgelines. The route features an immediate and significant climb, tackling the lower slopes of Yr Wyddfa (Snowdon) and then plunging runners into a world of challenging terrain. Expect rocky paths, steep scree, potentially boggy sections, and areas requiring hands-on scrambling as you traverse iconic peaks like Glyder Fawr, Pen Yr Ole Wen, Carnedd Dafydd, and Carnedd Llewelyn. While less extensive than the 100M, this course packs a punch, demanding exceptional focus, agility, and mountain experience. Runners often report the terrain being less runnable in sections than even the longer race, emphasising its technical nature.

The Ultra-Trail Snowdonia 100K by UTMB is more than just a normal ultra marathon; it's an immersive journey through a wild and ancient landscape, a profound test of mental and physical fortitude, and an unforgettable adventure for those brave enough to take on Eryri's mountains.

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