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Boréalys Mont-Tremblant by UTMB

Boréalys Mont-Tremblant by UTMB (Odyssée 100K)

Village Mont-Tremblant

81 km+6,233 m D+🏔️ 2,480 mTechnical mountain ultra

Race guide

Updated 29 June 2026

The Odyssée 100K at Boréalys Mont-Tremblant by UTMB is a mountain ultra that packs a serious punch into 81 kilometres and 6,233 m of vertical gain, starting and finishing in Village Mont-Tremblant at 1,036 m elevation. Despite its nominal '100K' billing, the course demands the same respect you would give a full hundred-miler — the density of climbing per kilometre is relentless, and the high point at 2,480 m means conditions can shift dramatically above the treeline. This is a race that punishes impatience and rewards runners who treat the first half as an investment, not a race.

Course Overview & Terrain

The race begins and ends in Village Mont-Tremblant, with the loop passing through the Base Nord crew point twice before returning to the finish at 80.7 km. The 6,233 m of accumulated elevation gain compressed into 81 km means an average gradient that keeps legs constantly loaded — there is very little flat running here. Expect a mix of rooted singletrack, rocky technical descents and open alpine sections above 2,000 m. The high point of 2,480 m places runners firmly in exposed mountain terrain where weather can turn quickly, and descent quality matters as much as climbing strength for protecting quads through to the finish.

The Decisive Climbs & Where the Race Is Won or Lost

With 6,233 m of gain distributed across 81 km, there is no single 'one big climb' to survive — the course stacks repeated ascents that compound fatigue over time. The second half of the course is where the race truly begins. Runners who have gone out conservatively through the early sections arrive at the later climbs with enough muscular reserve to push; those who raced the first half find the back end becomes survival mode. The passage through Base Nord on both loops is a critical checkpoint to reassess: use crew access to refuel, check your pacing split honestly and reset mentally before committing to the second half push. The final kilometres back into Village Mont-Tremblant carry a hard cut-off of 23:41 on Day 2, which gives a firm ceiling but also rewards anyone who has banked time wisely.

Pacing Strategy: Patience as a Weapon

The single biggest mistake in a race with this elevation profile is mistaking early energy for fitness. The proven approach here is to run the first half almost sociably — if your effort feels 'too easy', it is probably right. That restraint is the deposit that funds a strong second half. Once past the midpoint and through Base Nord for the second time, you can begin to trust your legs and gradually lift the effort. Break the remaining distance into manageable segments rather than staring at the total: two climbs at a time, one aid station at a time. This mental reframing — 'two more and I'm home' — turns a wall of fatigue into a series of small, achievable targets. The runners who finish strongest here go easy early, not hard.

Fuelling & Aid Station Approach

With a potential finish time stretching close to 24 hours for many runners, fuelling must be systematic rather than reactive. Aim to eat real food early while your gut is still happy and reserve gels or easy-to-digest options for the demanding back half when appetite typically drops. Hydration needs will vary significantly with altitude and conditions — arriving at Base Nord slightly ahead of your fluid targets on the first pass gives you a buffer for the second loop. Use the crew access at Base Nord strategically: resupply drop bags, change socks if conditions have been wet, and take 3–5 minutes to eat something substantial rather than grabbing snacks on the move. Going into the second half properly fuelled is worth more than the time saved by a rushed stop.

Conditions to Expect

Village Mont-Tremblant sits at 1,036 m, but the course climbs to 2,480 m, meaning runners will experience meaningfully different weather zones during the same race. Lower sections in the valley can be warm and humid, particularly if racing in summer conditions, while the high alpine terrain above 2,000 m can be cold, windy and exposed. Pack mandatory kit for mountain conditions and do not rely on what it feels like at the start line. Heat in the lower sections earlier in the race can be managed with planned cooling resets at crew points; cold exposure at altitude later in the race requires layers you can access quickly on the move. Check the forecast the morning of the race and prepare for both extremes — in mountain ultras at this elevation range, encountering both in the same event is not unusual.

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Checkpoints & cut-offs

Course data verified against the official source (2026-07-05) · official source

Start – Village Mont-Tremblant

0 km · 230 m ·

Lac Gauthier

12.8 km · 294 m ·

Domaine Saint-Bernard

18.3 km · 276 m ·

Pic White

33.7 km · 867 m · Sat 13:00

Base Nord

43.8 km · 357 m · Sat 15:15

Edge

53.5 km · 839 m ·

Nansen

60.9 km · 388 m ·

Edge

65.9 km · 838 m ·

Base Nord

70.3 km · 358 m · Sat 21:30

Finish – Village Mont-Tremblant

80.7 km · 230 m ·

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