Figure of Eight Loop at Grand Som

Petit Som and Grand Som from Gîte à Rucher de la Ruchère.

Technical sheet
No. 5650
A Saint-Pierre-d'Entremont walk posted on 20/05/12 by 6beryeti. Update : 04/10/16
Calculated time Calculated time: 9h00[?]
Distance Distance : 17.77km
Vertical gain Vertical gain : 1639m
Vertical drop Vertical drop : 1639m
Highest point Highest point : 2007m
Lowest point Lowest point : 1165m
Difficult Difficulty : Difficult
Back to starting point Back to starting point : Yes
Walking Walking
Areas Areas : Alps, Chartreuse, Dauphiné
Location Location : Saint-Pierre-d'Entremont (73670)
Starting point Starting point : N 45.408314° / E 5.796489°
Map IGN Map (Click to buy) : Ref. 3334OTR
Download : -


A middle mountain route that is nevertheless quite Alpine. To be done preferably in dry weather. This route is to be hiked in the indicated direction so as to traverse the two true difficulties (the couloir of Petit Som and the southern ridge of Grand Som from La Suiffière) while going uphill. The remainder is in forests or mountain pastures.

From Ruche à Gîter (D), follow the Tour de Chartreuse PR Trail south passing through Le Tracol (1) until Col de la Ruchère (2). In the pasture, leave the trail you're on taking the steep couloir of Petit Som (3) in the NNE direction to reach the summit (4).

Descend (east) towards Col de Léchaud (5) (limestone pavement, watch your ankles) then cross a rocky ridge to descend to Col de Bovinant (6). At Habert de Bovinant (11), continue south in the Mauvernay valley (obvious) to Col de Mauvernay (7).

A small trail in the scree leads to the ridge of La Suiffière and Pas de La Suiffière (8).

You are on the southern ridge of Grand Som. A small trail climbs (north) to the summit (9).

After a picnic break and well-deserved panorama, follow the yellow-marked trail south. At the point where it seems to want to turn to cross over (west) the rocky outcropping, continue a bit longer until you come across a moderately steep valley (10) where you will quickly find the trail that easily crosses an opening in the outcropping.

Reach Col de Bovinant and Habert of Bovinant (11) for the second time and again follow the Tour de Chartreuse (PR trail) in the SW direction. At the point where you meet an outcropping, leave the trail you're on and head in the NNW direction following the route of Pas du Loup (12). Then reach Col de la Ruchère (2). Set out in the SW direction to reach Prairie de La Folie and Habert Billon. Set out again north to cross Col de l’Aliénard (13). Keep descending north to reach the Tour de Chartreuse which brings you back to the starting point (A).

Waypoints :
D/A : km 0 - alt. km 0 - La Ruche à Gîter
1 : km 2.32 - alt. km 2.32 - Le Tracol
2 : km 3 - alt. km 3 - Col de la Ruchère - Col de la Ruchère
3 : km 3.82 - alt. km 3.82 - Steep couloir of Petit Som
4 : km 4.12 - alt. km 4.12 - Petit Som - Petit Som (1772m)
5 : km 4.28 - alt. km 4.28 - Col de Léchaud - Col de Léchaud
6 : km 4.74 - alt. km 4.74 - Col de Bovinant - Col de Bovinant (1646m)
7 : km 6.2 - alt. km 6.2 - Col de Mauvernay - Col de Mauvernay (1774m)
8 : km 7.65 - alt. km 7.65 - Pas de La Suiffière - Pas de la Suiffière
9 : km 8.34 - alt. km 8.34 - Grand Som - Grand Som (2026m)
10 : km 9.89 - alt. km 9.89 - Moderately steep valley
11 : km 10.32 - alt. km 10.32 - Col de Bovinant and Habert de Bovinant
12 : km 10.73 - alt. km 10.73 - Pas du Loup - Pas du Loup (Chartreuse)
13 : km 14.78 - alt. km 14.78 - Col de l'Aliénard - Col de l'Aliénard
D/A : km 17.77 - alt. km 17.77 - La Ruche à Gîter

Useful Information

To be avoided while snow is present in the couloir and on the southern ridge.

Ruche à Gîter (cross-country ski lodge) is a very pleasant stop when returning. It offers local products starting with excellent carbonated hop-based recovery drinks!

We advise taking IGN maps with you on this walk. Click here to buy : 3334OTR.

Visorando and this author cannot be held responsible in the case of accidents or problems occuring on this walk.

During the walk or to do/see around

Believer or non-believer, one can only note that this place is strongly influenced by men of faith.

Le Monastère de la Grande Chartreuse (Monastery of the Grande Chartreuse) and Le Musée de la Correrie (Museum of the Correrie).

L’église de Saint Hugues de Chartreuse (Church of Saint Hugues of Chartreuse) decorated by the painter Arcabas with a great deal of faith, liberty and even humour.

This is obviously a pristine place in the mountains for livestock and agriculture. It’s also a region for sports and recreation with all mountain activities (hiking, climbing, skiing) as well as the Saint Pierre de Chartreuse Trailrunning Station.

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The GPS track and description are the property of the author.