Climb up to La Ruchère, heading towards the Nordic centre. Walk past the mast, and at the Cleyat lodge, turn left. Follow the road through the forest and park just before Le Habert.
(S/E) Head towards the Col de Léchaud, passing the Habert. This section is straightforward, and the path is clearly marked in yellow.
(1) Once you reach the pass, take the path to the west which climbs to the summit of the Petit Som.
(2) Take a moment to admire the view. Head back down to the Col de Léchaud.
(1) Head straight on towards the Habert de Bovinant. Here too, the path is well marked.
(3) Just past the habert, do not continue along the marked path, but head south onto a small, barely visible track which will take you to the Col de Mauvernay, which you can see directly ahead of you. Once past the pass, the path flattens out and you will soon reach a scree slope. Take care: the path is narrow and not very visible. Fortunately, you’ll be guided by a few cairns.
At the end of the scree slope, join a signposted path coming from Saint-Pierre-de-Chartreuse. Follow it uphill to the left towards the Pas de la Suiffière. On this section, take your time and keep a close eye on the signposts every so often so as not to get lost.
(4) Continue along the signposted path to Le Racapé.
(5) Turn left towards the summit of the Grand Som. This section is quite steep, so take it at your own pace.
(6) At the Grand Som, take in the new panorama, which this time offers lovely views of the Belledonne and Bauges mountain ranges, and even Mont Blanc.
Follow the Sentier des Moutons to the right (north) towards the Habert de Bovinant.
(3) This time, head west towards La Correrie.
(7) At the signpost, carry on straight ahead along the path that leads downhill. You’ll come to a junction (marked ‘Bourdoire’ on the map).
(8) Turn right. After 100m, do not follow the signposted path that branches off to the left, but carry on straight ahead.
Follow the forest track to the next junction, where you’ll come across a signposted path again.
(9) Turn right. The path climbs through the forest for about 500 metres, then opens out onto a meadow. Carry on to the Col de la Ruchère.
(10) All you have to do now is head towards Le Clayet via the Oratoire Teste de Lavines. Turn right after about 200 metres, then carry on straight ahead. Just past the Habert car park, you’ll return to your starting point (S/E).