Montagne de Glandasse, long circular loop

Head up to Châtillon-en-Diois.

(S/E) Start at Rue du Reclus. Facing the post office, turn right onto Rue de la Baurie, then turn left at the junction to join Rue de l’Église. Then turn right onto Montée du Tricot.

(1) Leave the road and the^GR®95, which continue straight on. Turn right onto the^GR®91path (marked in red and white), which climbs through pine trees and Mediterranean vegetation. A steep climb (1,200 m elevation gain)

(2) At the final hairpin bend before the plateau, the start of the path is clearly visible to the right of the ledge, heading towards the Source de Baume Rousse. There are no signs or markings.

(3) Source de Baume Rousse: make sure you drink plenty of water and top up your water bottles, then retrace your steps.

(2) Turn right and head due north.

(4) Large cairn at the edge of the plateau. The small cairns that follow – useful in foggy conditions – lead to the Cabane de Châtillon. 50 m to the right of the path, clearly visible, is the Grand Assiriau, a chasm and glacial cirque.

(5) The rustic, unmanned Châtillon Hut, next to a man-made pond. Cross the Col de la Raille, then temporarily leave the^GR®91at the Col de Guignaise by turning left to head towards Les Aravas in a north-westerly direction. Continue on, passing beneath the Roc d’Ambane, and head north along the obvious path towards the summit of the Dôme or Pié Ferré, the highest point of the Montagne du Glandasse (2041 m).

(6) Descend northwards by eye to rejoin the^GR®91, which bypasses the summit. Follow the^GR® to the left, following its red and white markings. Markings and cairns often require careful attention to avoid getting lost.

(7) Alternative route. A two-day hike with an overnight stay in one of the Chaumailloux mountain huts, 4 km off the main route, not far from the Pas de l’Aiguille: take the^GR®91and 93 northwards for 700 m, until you reach the unmarked and poorly signposted crossroads at Quatre Chemins du Jas Neuf. A metal post set slightly apart marks the spot; the pond, which is often dry, is not very noticeable. From this crossroads, following the flat, easy path heading north-east – that is, walking straight towards Mont Aiguille – you will pass the large Bergerie du Jas Neuf halfway along, and after a short final descent you will reach the hexagonal wooden PNRV mountain hut or the Bergerie de Chaumailloux. There are two springs nearby. Have a good night’s sleep. The next morning, return to the Quatre Chemins de la Ville.

(7) Do not follow any of the directions shown on the signposts at the Quatre Chemins de la Ville. Take the path, marked with black dotted lines on the IGN map, down the valley which descends south-east for 450m, then turns south. The path gradually leaves the valley floor.

(8) Just before a scree slope crossing the valley, a faint path begins, rising to the left; it is not marked on the IGN map. Its small cairns are fairly easy to spot on the ground. Following them, you’ll rejoin the path shown on the map—which is also marked with cairns—leading to the old Jasse du Jardin du Roi.

(9) Head up the valley towards the east.

(10) Leave the path that seems to follow the natural course of the valley floor. Head uphill to the right, then follow the cairns to the Bergerie du Jardin du Roi and its plastic drinking troughs.

(11) Head south-west to reach some ruins.

(12) The author, without a GPS, lost his way from these ruins, unable to find the path marked on the IGN map. Walking generally southwards, I came across a faint track that had already been used by motor vehicles. It could only lead to the Bergerie de Tussac and its huts.

(13) Continue to the left. The track runs along the edge of the plateau, then winds its way down to the D515.

(14) Turn right and follow the road down to the village of Benevise: at last, a fountain!

(15) Just after the hairpin bend in the village, turn right onto the track (which becomes a footpath) signposted towards the village of Menée: another fountain!

(16) There are 7 km left on the D120 to complete a circular route, passing by and following the River Bez.

(17) Hitchhiking is allowed, but success isn’t guaranteed. Arrive at Châtillon-en-Diois (S/E): so many fountains – it’s paradise!

Water: allow at least 3 litres of water per person. The only water source on the upper part of the route is the precious Source de Baume Rousse (3), 150m off to the right of^{the GR®91}. It is not signposted. It is easy to find by following the ledge from the start of the final hairpin bend (2) before reaching the Plateau du Glandasse. The water does not flow from a pipe. It is a small reservoir built into the cliff face, sealed by a hatch. Bring a cup to avoid having to dip your hand in to fill your bottle. Is there any water left there at the end of summer after numerous walkers have passed through? The water is crystal-clear, cool and drinkable, provided those who have gone before have taken care of this treasure. The next water source on the route is the fountain in the village of Benevise, 20 km further on.

For those doing the route over two days, the recommended overnight spot is near the Chaumailloux and Chevalière springs

Two-day alternative: to have shelter with a water source near the halfway point, we suggest spending the night at the PNRV hut in Chaumailloux or at the Bergerie de Chaumailloux

Navigation: on the Vercors High Plateaus, even on^{GR® routes}, it is not uncommon to temporarily lose the path. A compass and a detailed map (or GPS) may be useful, particularly between (7) and (13)

Difficulty: the route is very long and involves a significant elevation gain. Navigating the Vercors High Plateaus in general, and the area between (7) and (13) in particular, requires careful attention and a bit of practice. The paths are sometimes narrow and poorly marked, but never exposed

- Baume Rousse ledge and spring.
- Sharp limestone pavement, cliffs, plateaus, chasms, ice pits.
- Montagne du Glandasse, Pié Ferré.
- Panoramic views over the Vercors High Plateaus, Grand Veymont, Mont Aiguille, Dié, the Drôme Valley…
- The Pas de l’Aiguille site and its Monument to the Resistance near the Chaumailloux Refuge
- Limestone grasslands.
- Wild tulips (the emblem of the Vercors Regional Nature Park) at Quatre Chemins de la Ville and a multitude of mountain flowers.
- With a bit of luck, you might spot ibex and chamois...