Park in the car park at the entrance to the village of Désert-en-Valjouffrey, on a bend in the D117.
(S/E) Cross the village. Cross a bridge over the Laisse and join theGR®54. Continue straight ahead (east-northeast) along the Bonne river.
(1) At an altitude of 1285 metres, continue straight ahead on the carriage road and ignore the path (not very well marked) that branches off to the left. Pass through the entrance to the Parc des Écrins.
(2) Continue along the wide carriage road parallel to the river until you reach the IGN marker.
(3) The road narrows as it approaches the Pisse waterfall.
(4) Leave the waterfall on your left and continue straight ahead.
(5) At the intersection, continue straight ahead to enter the glacial valley. A little further on, as the path changes direction, note the summit of Olan coming into view. From here on, you will not lose sight of it.
(6) Pass in front of the Châtellerat shepherd's hut. Be careful, you are crossing a grazing area where the sheepdogs are keen to do their job...
(7) At another intersection, continue straight ahead towards the refuge. Ignore a turn-off on the right and stay with the stream on your right. The climb becomes steeper.
(8) Take a sharp left turn. At the hut, turn right and continue climbing to reach the first Font Turbat refuge.
(9) Continue climbing and pass the second refuge.
(10) At the intersection, turn left (north-northwest) towards the small valley. The trail climbs steeply for 300 metres. Follow the red round markings and cairns (the trail is less frequented). Reach the Col des Lauvets, where the view is superb: on one side is the Olan and on the other is the glacial valley with the Là Pisse waterfall at the bottom.
- Message from misouli169lesbasbleus 07/19: It has recently been re-marked in bright orange + cairns, so there's no way to get lost.
(11) Start descending, heading north-west, passing through a scree slope: watch out for possible rockfalls.
(12) At the intersection, turn left (west) and continue downhill (do not take the small path that goes up to the right).
(13) You will reach a mountain pasture where you can see the remains of an old wall and the ruins of Le Petit Vallon. Continue descending into the glacial valley via a series of small hairpin bends.
(7) Turn right and follow the same path as on the way up to return to the car park (S/E).
– and that's still more than 20 kilometres of walking with over 900 metres of elevation gain!