Previously listed to be 2,770 meters high, the official summit of the Col de l’Iseran on recent maps is now shown at 2,764 meters. That still makes it the highest paved pass in Europe, although the artificial loop around the Bonette is claimed as such by the French.
However, the official pass height of the Bonette is 2,715 meters, so the Iseran, the Stelvio (2,758) and the Agnel (2,744) are higher ‘by nature’…
The Iseran is part of the Route des Grandes Alpes (in French). It connects the valleys of the Isère (Tarentaise) and Arc River (Maurienne) between Val-d’Isère in the north and Bonneval-sur-Arc in the south.
The north side of the pass officially starts at Val-d’Isère, or further down from Bourg-Saint-Maurice. The climb from the south officially starts at Lanslebourg-Mont Cenis, but you could also consider Modane as the starting point.
Post WWII the Iseran was included in the Tour de France 5 times between 1947 and 2007 – in 1996 it was also scheduled, but that stage was rescheduled due to bad weather (snow on both the Iseran and the Galibier).
While those grades seem rather friendly, the sheer length of the climb makes it a hard one. Plus, not considering the two 9 kilometer ‘near flat’ sections at the bottom and through the tunnels past the lake of Tignes, the average over the remaining 30 kilometers is close to 6%.
The views higher up, past Val-d’Isere, are fantastic, as is the panorama at the summit. Report of my trip up this end in 2014 here.
The first 7 kilometers are up the Col de la Madeleine (not the Madeleine), with some 350 altimeters not the hardest bit. After that, there’s a 12 kilometer ‘flat’ section through the Bessans valley.
Without that section, the average of the climb increases to around 6%. The hardest part starts at Bonneval-sur-Arc: 13.4 km with 977 m of elevation (7.3%) with several stretches over 10%.
I descended this way towards Modane after my climb from Bourg-Saint-Maurice, with a little ‘detour’ up and down the Mont Cenis. Thinking this was mainly downhill, I figured it would be relatively easy. However, the section in the valley between Bonneval and la Madeleine, completely wore me out because of the strong headwind.
If you go the other way and would then also have to battle a headwind, you will face a very tough 12 kilometers – despite being used to riding headwinds (the famous ‘Dutch Mountains’), I know I would not be happy.
If you also include the section between Modane and Lanslebourg as a ‘warm up’, you can add some 23 kilometers with an additional 450 meters – including some up- and downhill bits – of elevation gain, but also here, the wind could be your greatest enemy, as I experienced first hand…
Image gallery of my trip up from Bourg-Saint-Maurice in 2014 on Google+