(S/E) Departure from the Natural Reserve House on the D36 between Chambon-sur-Lac and Courbanges.
Follow the discovery path due South-West passing nearby the Perouse cascade (1)do not miss the indications for coming and going on site. Return to the discovery path and head North West towards the cabin and the Sainte Anne spring (old project of a thermal resort) (2).
After the bridge, at the junction, take the left heading South West for about 600m
(3) At the next crossing, leave the path to your right and take the path in front heading South. After a left turn, leave the path toward the Biche (Deer) cascade (4) and continue on a steep climb, first due North East, then South. It leads grassy underwood to a plateau and to the Chambgourdeix volcanic hill (1570m) (5).
Turn due West on the crest line (chemin de crête) bordering the valley (leave the small pathways returning to the main path to your left), walk past the Perdrix (Partridge) volcanic hill or puy, then to Puiy Ferrand. Following this ridge, due North West, go downhill towards the Cabanne pass and then start a steep Puy de Sancy ascent (6).
Go back down the path on the Pas de l"Ane (Donkey pass) (7). Turn right, due North, and the telecabin pylons (8) then cross a depression heading North East, then East, on GR4E for about 1.2km
(9) Mât de la Dore: take a perpendicular right turn towards the South on the path to Pan de la Grange 500m away (10). Turn left, follow the GR4 along the Puy crests that mark the separation between the Chaudefour and the Dore valleys
(11) Once you get to the Puy des Crebasses , leave the GR4 to your left, and head due North East towards Chambon-des-Neiges.
(12) At the next crossing, go downhill to the right in the Chaudefour valley direction - don't forget to admire the Liadouze rocks, the Spite peak, the Cock and Monk crests, and other volcanic dikes.
Soon you will reach the same path you came in from at the beginning of the walk. Follow it to the left to Natural Reserve House and your departure point(S/E).
