The Marmotte is the archetype of a high‑alpine granfondo: a mass of determined riders rolling out of Bourg d’Oisans at dawn, threading a set of truly legendary cols before that mythic, crowd‑lined finish on Alpe d’Huez. It’s a true bucket‑list day, drawing thousands from across Europe—think the Alpine counterpart to the Maratona dles Dolomites or L’Étape du Tour, with a dash more bite.
Route overview
Expect roughly 174–186 km with around 5,000–5,500 m of elevation gain. The classic sequence is:
- Col du Glandon: ~21 km at ~6–7% to ~1,925 m. A long, irregular opener that sets pacing discipline for the day. The descent is often neutralised for safety.
- Col du Télégraphe: ~11.8 km at ~7.3%, a steady forested climb to Valloire.
- Col du Galibier: ~18 km at ~6.9% to 2,642 m; thinner air and exposed ramps bite in the final kilometres.
- Col du Lautaret: transition/descent with tunnels—front and rear lights are mandatory.
- Alpe d’Huez: ~13.8 km at ~8% with infamous early ramps over 10–12% through the first bends.
What makes it special (and hard)
It’s the cumulative load: Télégraphe into Galibier stacks nearly 2,000 m of climbing before you even see Alpe d’Huez. Altitude, temperature swings (valley heat, summit chill), and long descents demand complete riding skills. Yet the reward is immense—glaciated vistas, Tour‑de‑France history on every hairpin, and a finish you’ll never forget.
Getting there
- By air: Grenoble (≈1 hr by road) is most convenient; Lyon (≈2.5–3 hrs) and Geneva (≈3.5–4.5 hrs) are solid alternatives.
- By rail/bus: trains to Grenoble SNCF, then regular buses to Bourg d’Oisans (check Transisère schedules; services can be limited early/late in the day).
- Parking: event parking zones open pre‑dawn in Bourg. Arrive early and heed road closures around the start.
Accommodation
Bourg d’Oisans fills quickly. Book hotels, apartments or guesthouses months in advance and look for cyclist‑friendly features (secure bike rooms, early breakfast). Excellent nearby campsites include Camping Le Colporteur and Château de Rochetaillée; mobile homes and tent pitches go fast for Marmotte week.
Facilities, registration and support
Start numbers are usually collected at the event expo the day(s) before—bring ID. Expect wave starts at first light, a bag drop to the Alpe d’Huez finish, medical and mechanical support, and multiple official feed zones (commonly including Valloire and later valley points—confirm the year’s route sheet). Cut‑offs apply at key points, including the base of Alpe d’Huez.
Pacing and gear
- Gearing: go low—compact or sub‑compact with 11–32/34 is sensible. You’ll thank yourself on the Alpe.
- Pacing: ride the opening valley and Glandon conservatively; keep a tempo on Télégraphe; save matches for late‑Galibier and the first five bends of Alpe d’Huez.
- Descents: the course mixes fast, technical sections and tunnels—use reliable lights, keep it smooth, and respect neutralised segments.
Nutrition and weather
- Fuel: aim for 60–90 g carbs per hour plus electrolytes. Eat early and often—don’t rely solely on gels. Two bottles, refilling at every opportunity, is prudent.
- Clothing: prepare for 10–28°C swings. Pack gilet, arm warmers and a light waterproof; thin gloves help on long, cool descents. Sunscreen is essential.
Typical times and mindset
Front riders may finish in 6–7 hours; most well‑prepared participants take 9–12. Respect the course, pace your day, and soak up the atmosphere—this is the Alps at their most inspiring. Check the official 2026 rider guide for final route, cut‑offs and feed locations.
