The route starts from Lachaup, a hamlet in the commune of Agnières-en-Dévoluy.
Park in the car park on the left near a pond (the water is drinkable).
(S/E) Take the tarmac road opposite, which very quickly turns into a track.
Follow it to the 1460m altitude (Serre Long) where you join theGR®93, which leads to the Col du Charnier beneath the Grand Ferrand.
(1) Leave the track and turn left onto theGR®93, following the grassy slope. Reach the Chourum Clot sinkhole hut.
(2) Continue along theGR® to the foot of the Roche Courbe cliff.
(3) Follow the outward route back to the car park (S/E).
: during the summer grazing season, see the notice dated 03/08/2022