The Col d’Ornon is not a very difficult pass (11 km at 6% on average).
If forms a junction between the Oisans and the Valbonnais. The road is quite uneven with a series of loops in the second part of the ascent. These are a bit tougher than the linear road in the first few kilometres (going up a valley). The view over the last kilometre and at the top is rather lovely, amid the pastures.
This fairly easy route through the whole beautiful Lignarre Valley is very popular with cyclists at the start of the season. The last kilometres before the pass are a little steeper than the rest of the route, but are not too strenuous.
Take this route in the morning when the mountains’ shadows provide cool shade.
From Bourg-d’Oisans, take the RN91 towards Grenoble. At the second kilometre, turn left towards Valbonnais - la Mure - Ornon via the D526.
The pass is at the 14th kilometre, where you can stop at the gîte or restaurant at the Col d’Ornon ski resort.