Climb: From Arc 2000 ski area, go to the top of the Grand Col chair lift by ski touring or the ski lifts (n°38, open at 9h30, altitude 2835m). While ascending, you can see "Grand Col" located between Aiguille Rouge on the left and the Mont Pourri massif on the right (Parc National de la Vanoise). You reach the pass via a short 20-minute climb (East). A basic refuge is located at the pass (alt. 2935 meters).

Continue to the right on the moraine (100m) to reach a broad flat area leading to the Grand Col glacier. While staying away from the north face of Aiguille St-Esprit (possible stone falls or avalanches), make a large ascending curve on the left bank of the glacier. Plumb with Col des Roches, when the crevassed slopes become steeper (S3/S4 for 200m), traverse to the left towards the rocky shoulder to the NW to cross the bergschrund (sometimes formidable sequence). Then continue towards the pass (South) via gentler slopes. A final generally good bergschrund leads to Col des Roches (3443m). It takes 1h30 to 2 hours.

From the pass, traverse on foot along a descending rock ledge which leads to a short chimney (handrail safety rope in bad conditions). A few meters lower, a short steep snow slope (20m, 40°) makes it possible to reach Geay glacier. Go up this splendid glacier while slaloming between seracs and crevasses. Cross several small steep pitches in S4 (exposed over hard snow). The last bergschrund, between 3400 and 3500 meters, can be difficult to cross. Then go right towards the "Shoulder" of Mont Pourri  (3650m) to reach the summit via the western ridge. The last fifty meters at 45° are often cleared (fresh ice and rocks). It takes 1h15.

Descent: Take the same route until under Col des Roche (sequences in S3/S4, expo 2/3). Then continue on Geay glacier, sometimes very crevassed (faces west); in its centre until the altitude of 3300 meters, then on the right bank to avoid the seracs. Under the south face of Aiguille du St-Esprit, the glacier heads towards the South to gradually disappear. Via a traverse on the right, you reach the large characteristic side moraine (alt. (2850m). Cross it and descend towards the SW to the place called "le Plan de la Citra" located at the foot of the SW ridge of Aiguille du St-Esprit. The Mont Pourri refuge is in the vicinity (alt. 2370m, water tap). It takes 1 hour 45.

Go up in skins of seal towards the north and cross a first plateau named "la Commune d'en Bas". At its northern end, a small steep pitch of 100 meters leads to "Commune d'en Haut " that also must be gone up. Pass a private chalet of Parc de la Vanoise (alt. (2,570m). At the northern end of a final plateau ("Lac des Mouton", 2574m), you reach Arc 2000 ski area. It takes 1h30. From the start of the Grand Col chair lift, follow the blue Vallée de l'Arc piste to reach the ski area.