Circuit of the Petit and Grand Som from La Ruchère

Park at the Ruchère car park (without driving up to the cross-country ski centre further up).

(S/E) Continue along the road, skirting the large estate on the right, until you reach the start of the path at the very end of this road (about 200 metres from the car park).

(1) Head south up a well-marked path which crosses forest tracks several times. You’ll reach a junction.

(2) Take the path branching off to the left and head eastwards, winding its way uphill.

(3) Cross the track and follow the yellow-marked path.

(4) Return to the logging track along the cliff face and emerge into a forest; cross it heading due south. Approach the Barre des Roches Rousses, then head back down to the base of the Petit Som summit to emerge at the Col de Léchaud.

(5) Continue climbing to quickly reach a small pass on the ridge.

(6) Head down towards the Habert de Bovinant, but cut northwards below the Col de Bovinant to rejoin the path that climbs up to the Grand Som. Please note: if there is fog, carry on until you reach the signs indicating the path at the pass. Follow the path eastwards then southwards to emerge onto the ridge of the Grand Som.

(7) Continue straight ahead along the Sentier des Poutons to reach the summit of the Grand Som.

(8) Take the path on the left, heading downhill, following the sign for the Pas de la Suiffière. You’ll reach the narrow pass.

(9) Pass through it, taking care of the rocks, and you’ll soon reach a crossroads of paths.

(10) Turn right and head uphill to reach the Pas de la Suiffière.

(11) Descend on the other side. Take care at the start – the path is daunting but fairly easy and becomes less steep very quickly. Reach the end of this steep section.

(12) Descend to the right over scree. After about a hundred metres, near a shrub, a path branches off due north, following a contour line. Follow it to cross the scree and reach a mountain pasture, then continue along the contour line, climbing slightly to cross a large valley. You’ll emerge at the Col de Mauvernay.

(13) Descend northwards through the valley to reach a sheepfold.

(14) Go well round it to the east, heading for the path that leads up to the Habert de Bovinant; take it to the left to join the GR®9 and the GRP® Tour de Chartreuse.

(15) Turn right onto the GR® and follow its red and white markings. Reach the Col de la Ruchère.

(16) Continue along the GR®, leave it to the right at^{the first} junction, then stay on this path, pass the Oratoire Teste de Lavines, and carry on to the Ruchère car park (S/E).

(7) You can top up your water supplies at Habert de Bovinant.
(7) Please note: from this point, the route to the summit is misleading and may dampen the spirits of those arriving on the ridge feeling a little tired. Allow a further 30 mins to reach the summit.
(12) Note: from here, there is a route leading up to the summit via the ridge. Very well marked, exposed but not excessively so, ideal for a change of pace. This can be done, for example, by walking the circular route in the opposite direction.

(5) Col de Léchaud: take a return trip to the summit of the Petit Som, situated a little further up to the west (30 mins return).
(7) On the ridge of the Grand Som: take in the scenery, including Mont Blanc, the Belledonne Range and the Vercors.
(8) Grand Som: a bird’s-eye view of the Grande Chartreuse Monastery.