This circuit is a classic of the valley, traveled indifferently from the refuge of La Golèse or Bostan. The Bostan pass marks the border with Switzerland.
Starting point: Le Plan aux Arches.
- Climbing time: 4 hours in good snow conditions
- Starting altitude: 1,096 metres
- Maximum altitude: 2,290 metres
- Difference in altitude: 1,194 metres
Follow the wide track at the end of the car park. It climbs steadily up through the lovely Bostan forest to an altitude of 1,450m. Carry on up to the Bostan mountain pasture chalets. There is a fine view of the Bostan dale, flanked on the right by the Dents D'Oddaz. Carry on along the left cwm towards Bostan refuge, or the narrower right cwm leading directly to Verdets Lake (which of course is invisible at this time of year). The Bostan hut has an annex in the form of a small chalet that is located behind the hut and is open all winter. Just beyond the hut, the path starts to climb more steeply towards the pass. The sign at the top marks the border with Switzerland. You can see the high, steep Dents du Midi and the Illiez valley. On the right, you can see the Massif des Dents Blanches and the Pas au Taureau pass. A few metres down the other side towards Pas de La Bide, there is the small Swiss emergency hut called Bossetan (Swiss spelling). The trip back down takes you along the same route.
From 12/22 to 04/15 : open daily.