Grand Ferrand via the sinkholes, return via La Vire Olympique

See the practical information for parking and recommendations.

(S/E) A cairn marks the discreet path leading north-northwest to the Canyon des Adroits. This path quickly veers west and reaches the thalweg of the Canyon des Adroits. Take note of the cairns and trees that mark the junction between the path and the thalweg so that you can easily find the path on your return.
Climb up the Canyon des Adroits following the stream bed. A fixed rope marks a narrow passage and can help you cross it when the rock is wet. Shortly after this narrow section (200 m), you will see a dark cave and an arch on the right (north) foothills. Continue west at the bottom of the valley until you pass a small rise, then turn right towards the northeast to climb up steep grassy slopes towards these landmarks.

(1) When you reach the Adroits arch and the adjacent cave, turn left due west to reach the sinkhole des Adroits after 250 m.

(2) This short tunnel ends under a rock, the base of which you then go around on the left (west) to reach steep slopes alternating between grass and rock until you reach the shoulder of the green Vallon Girier. Climb up the valley, observing the numerous karstic caves.
Shortly after these karstic caves, join a path below the summit of Soleil Bœuf. At IGN elevation 2143m, leave this path to climb towards the Pas de la Cloche, which is clearly visible to the left (west) of Soleil Bœuf, then head north through the scree leading to the Pas de la Cloche.

(3) From Pas de la Coche , locate the exit of the Olympique ledge ( see photo) , then take the path running through the scree towards the south-west under the rocks of Pic de la Cloche. Do not take the very first weakness to climb northwards, but wait for easier scree. Climb this scree in a zigzag pattern until you see the dark entrance to a small cave in very steep grassy slopes. Climb up to this cave entrance starting from the right of the grassy slope and zigzagging upwards. It is possible to climb higher than the cave, to the pass that separates the summit and the secondary summit of La Cloche (see trail on the map), but this is not essential. Put your walking sticks in your bag before entering the sinkhole.

(4) The Cloche sinkhole is a tunnel that starts a few metres to the right before turning completely left to reach a narrower (and darker) point leading quickly to the exit a few metres higher up. A headlamp can be helpful the first time. Below the exit, a small rope strap indicates that you are on the right track.
The exit is on a very (very) steep grassy and rocky slope that opens onto a grassy ledge to the north, allowing you to see the rest of the route to the west.
From here, the difficulties fade away. Simply climb up the ridge line due west towards the Grand Ferrand. The ridge is spacious and much easier than the adjacent slopes. After 2-3 camel humps, you will reach the normal route to Grand Ferrand, which also continues along the ridge, veering north-west. Reach the flat scree slope on the ridge.

(5) Continue northwest to reach the summit of Grand Ferrand, which can be reached via good rock steps.

(6) From the summit, you can descend to admire the Arches Interferrantes, a system of rock bridges connecting the Petit and Grand Ferrand. To do this, head north-northeast until you reach the escarpments.

(7) Return to the summit of Grand Ferrand before descending via the ascent route to the plateau identified earlier.

(5) This plateau marks the start of the Olympique ledge. Descend the steep slope heading due north for about 50 metres through the scree, before turning left (west) to follow the contour line until you reach the gaping hole of the sinkhole of the Chourum Olympique. This can be seen from a distance. Go around this chasm at its lower part (to the east) and follow the edge of the cliff to the end of the scree of the Olympique ledge.

(8) You will then come to the cliff below Pra Purc. A fairly steep couloir descends south-east towards the Goutourier depression, where there is a long-lasting snowfield in summer. Take this couloir, which poses no difficulty: its ledges are easy to climb down with good handholds, and you can simply let the stones roll down the scree.
You will quickly reach the Goutourier sinkhole, then climb up to the IGN 2262m contour line and take the wide Vallon du Grand Villard valley. There is no need to go through the scree (contrary to the GPS track shown here), as the grassy slopes are perfectly suitable.

(9) When you reach a small plateau near the 1994m contour below the Baume Fromagère, do not try to climb up to the right on the path through the scree, but descend south-east on the easy grassy slopes to reach the plateau bordered on the east by the Barre des Fontaines. Then turn south, almost level, to reach the steeper slopes that you climbed at the start of the walk to reach the Arche des Adroits.

Descend towards the Canyon des Adroits, without trying to take the steepest route, but always heading south-west.
Once in the bed of the Canyon des Adroits, head east to reach the cairns you spotted on the way up and follow the path leading back to the starting point (S/E).

Park in the only circular of the carriageway that heads north from Lachaup, leaving the road clear for agricultural vehicles (2-3 spaces to park on the grass).

? Water is not abundant, as is often the case in Dévoluy, so make sure you bring enough with you. There are a few springs at the bottom of the valley, but they only trickle.

To my knowledge, dogs are allowed in this part of Dévoluy, as it is outside the Vercors National Park (which includes Rocher Rond but not Grand Ferrand). However, this hike is beyond the capabilities of most dogs.

?‍♀️ This hike is rated "extremely difficult" due to the exposed slopes and the difficulty in finding the route. ⚠️ Do not attempt this route if rain is forecast or if it has rained in the previous 24 hours.

? The hike is well suited to bivouacking. It is possible to bivouac in the sinkhole des Adroits (2), which is equipped with comfortable pallets, or at the summit of Grand Ferrand if you want to see the sunrise (bivouac shelter).

In addition to standard hiking equipment, a helmet is essential to protect against rock falls caused by the numerous chamois, particularly in the Pas de l'Étoile (8). A head torch will help you see more clearly in the sinkhole de la Cloche. Telescopic poles (which can be stored in your rucksack in the sinkhole de la Cloche) are very useful on the descent. High-top boots are highly recommended, as two-thirds of the route is over scree.

⏰ Setting off early (before dawn, i.e. 1 hour before sunrise) will allow you to see the splendid colours on the Vallon Pierra and Roche Courbe peaks. Wildlife is also much more visible in the morning.

? The IBP statistics for the route give an index of 166, a distance of 12.87km, a cumulative elevation gain of 1477m, a walking time of 4:11:35 and an average speed of 3.07km/h.

Orientation is easy because the terrain allows you to always know where the cardinal points are, however, finding the route is difficult the first time: some passages seem unlikely. Read the description and photo captions carefully, and use the Visorando app on your GPS phone to follow the trail.

? Griffon vultures circle above the sun-heated scree from around 10 a.m., but you can sometimes see them perched on the yellowed grass of the Girier at dawn. Chamois can be seen earlier and are very numerous in the Vallon du Grand Villard.

The views from the peaks and passes are magnificent. See this interactive spherical photo. But the most beautiful spot is the very wild Vallon du Grand Villard, where there are many chamois.

An annotated panorama of the peaks to the south-west, north and south-east of the summit is also available.

Several variations are possible:

It is possible to push on to Petit Ferrand depending on the time of arrival at the summit. If you arrive late, it is also possible to return via the normal route and then via the Vallon Froid (leave the path on the plateau at around 2150m to descend eastwards towards the bottom of the Vallon de Charnier and the Adroits canyon).

At the point (9), you can climb up the scree slope to the right to reach a small unnamed pass overlooking the Girier hanging valley. This very green valley is dotted with karstic caves. You then have to descend by sight via steep slopes (making zigzags) to the IGN 1846m contour line to rejoin the route.

A few words of Devolved vocabulary:

• A karstic cave is a small limestone sinkhole.
• A baume is a cave, usually under a rocky overhang, which provides shelter from the rain.
• A sinkhole (pronounced choure-un) is a tunnel in a limestone mountain.
• A vire is a narrow, often level path that passes through a system of cliffs. In the Vercors and Chartreuse regions, a vire is called a sangle ( masculine noun).
• The word Adroit derives from adret and has nothing to do with skill: it is the sunny side of a slope.