Plate Longe and Coste Belle

Start from the car park at the Cabane de l’Avalanche. This point can be reached from Saint-Étienne-en-Dévoluy, heading towards Le Forest via the D17. Continue along the D417, then take the Bois Rond forest road (suitable for any vehicle if driven with care) on the left at Pont du Villard, heading towards Pré Grand.

(S/E) Head up the clearly visible valley towards the south-west, following a fairly well-marked, zigzagging path.
Climb above the tree line at around 1,650 metres, then continue up to around 1,700 metres.

(1) Then leave the well-marked track which branches off to the left towards the south-east, heading for a sheepfold and then the Vallon d’Âne, and continue straight ahead, due south, along faint tracks (several possible routes). Join a path coming in from the right at around 1,870m.

(2) Continue along this path through the valley between La Corne and Coste Belle and reach the pass at 2,048m.

(3) Leave the level path heading towards Combe Ratin. Continue almost due south, climbing slowly over scree and grassy slopes until you are directly below the 2,197m pass. You are now at an altitude of around 2,100m.

Then climb as best you can towards the pass. This is the trickiest part of the hike. You must proceed with caution and choose your route carefully, making use of the few sheep tracks, small grassy ledges or stable sections.

(4) The pass is wide, grassy and comfortable. The distinct ridge that follows is broad and easy to follow right up to the summit of Coste Belle.
From the summit of Coste Belle, the descent down the grassy, stony slope is quite steep at first but gradually levels out. There is no marked path. Head down as best you can in a north-easterly direction.

(5) At the bottom of the slope, head due north and join the path, at around 1,700 metres, leading to the sheepfold mentioned on the ascent. Follow the path descending from the Vallon d’Âne towards the north-west for a few dozen metres and rejoin the ascent track.

(1) Follow the same route down to the start (S/E).

Alternatives:
- You can also easily reach the start point from the Bure cable car car park by following the D417. Then continue along the track to reach the Cabane de l’Avalanche car park. This adds 500 metres to the hike.
- In (5), the route can be adapted to suit your preferences to reach the Vallon d’Âne path; from there, head due east towards 1,900 metres to reach the path to the Chalet du Vallon d’Âne at around 1,780 metres. About a hundred metres before the chalet, follow the path that branches off to the left, heading north-west, to reach the sheepfold mentioned on the ascent.
- If you are put off by the climb to the 2197 pass, you can always opt for the very easy ascent of La Corne, skirting it to the north, which takes you over gentle grassy slopes without any difficulty.