Wildstrubel by UTMB®
Wildstrubel by UTMB® – Wild Glacier Marathon Lenk
Lenk → Crans-Montana
Race guide
Updated 18 July 2026
The Wild Glacier Marathon Lenk is the marathon-distance crossing in the Wildstrubel by UTMB weekend: 42 km with 2335 m of positive gain, starting in the Bernese Oberland village of Lenk and finishing across the mountains in Crans-Montana. Despite being the shortest of the crossing formats, it still climbs to a high point of 2755 m, so it packs a full high-alpine day into a marathon. What defines this race is its compactness — there is very little flat, and almost no easing-in. From the moment you leave Lenk the course is either climbing toward its glacier-side high point or descending toward the finish, which makes it a punchy, concentrated version of the Wildstrubel experience for runners who want the summit and the Valais finish without the 55 or 70 km build-up.
The course: Lenk to Crans-Montana over the tops
The route starts in Lenk at 1065 m and climbs steadily to Iffigenalp at 1583 m by 13.6 km — a gentle-gradient opener that lets you settle before the serious climbing. From Iffigenalp the trail pushes up into the high country to the Cabane Wildhorn at 2302 m (20.7 km), the last checkpoint before the day tips over its 2755 m high point. The back half is a long descent with a crossing flavour: from the tops the course drops to the Barrage De Tseuzier reservoir at 1778 m (30.4 km) and then runs the final stretch down to Crans-Montana at 1498 m by 41.7 km. Like the other Wildstrubel formats, this is a true region-to-region crossing — you leave the Oberland side at Lenk and finish on the sunnier Valais slopes above the Rhône valley, ending the day roughly 430 m higher than a valley floor but well below where you have been.
Where the race is won and lost
The decisive effort is the climb from Iffigenalp at 1583 m to the Cabane Wildhorn at 2302 m and on to the 2755 m high point — the sustained push into the high country that dominates the middle of the race. Reaching Iffigenalp comfortably at 13.6 km is easy to do too fast on the friendly early gradient; the mistake shows up on this climb, where the altitude and pitch expose anyone who spent too freely on the approach. The second place the race turns is the long descent off the tops toward the Barrage De Tseuzier at 1778 m — well over 900 m of drop from the high point in a single sweep. On a 42 km course it is tempting to treat the downhill as free time, but this is loose, high-mountain terrain and the quads take a beating. Runners who keep the Wildhorn climb controlled and descend within themselves are the ones still running cleanly on the final leg from the barrage into Crans-Montana.
Pacing and fuelling to the cut-offs
Two checkpoints set the clock, both on the Friday: Iffigenalp at 13.6 km closes 11:30, and the Barrage De Tseuzier at 30.4 km closes 16:30. The Iffigenalp cut-off arrives early and behind the first sustained climb, so even a conservative start needs to be honest about pace. The most demanding block for time is Iffigenalp to the barrage — 16.8 km that contains the entire high crossing over the Cabane Wildhorn and the 2755 m point, with the Barrage De Tseuzier cut-off waiting on the far side. For fuelling, treat the summit crossing as the self-sufficient heart of the race: from Iffigenalp you have only the Cabane Wildhorn before a long stretch of high, exposed ground, so leave Iffigenalp fully topped up on calories and fluid. Crew access is available at the start in Lenk, at the Barrage De Tseuzier and at the Crans-Montana finish, so plan your handovers around the barrage as the key mid-race meeting point after the tops.
Conditions to expect up high
Although it is only a marathon in distance, the Wild Glacier Marathon Lenk spends its middle hours between roughly 1780 m and its 2755 m high point, firmly in high-alpine and glacier-adjacent terrain. The Cabane Wildhorn and the ground around the high point are open and exposed, where wind, rapid cloud and a steep temperature drop can arrive quickly even on a settled day, and snow lingering on shaded high sections is plausible early or late in the season. Carry mountain kit even though the race is short. Lenk at 1065 m may feel mild at the start, but you will be near 2755 m and fully exposed by the middle of the day, so a wind layer, warm top and gloves are worth their weight in the pack. The finish side above Crans-Montana tends to be sunnier and drier than the Oberland approach, so be ready to switch from managing cold on the tops to managing heat and hydration on the long descent to the line.
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Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-17) · official source
0 km · 1065 m · —
13.6 km · 1583 m · Fri 11:30
20.7 km · 2302 m · —
30.4 km · 1778 m · Fri 16:30
41.7 km · 1498 m · —
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