Upper part : Dôme de la Lauze (3568m) - Glacier de la Girose - Col du Lac (2963m). From Dôme de la Lauze or the summit of the Girose glacier ski lift, go completely north on the glacier leaving the ski lift on the right, towards a rocky spine which points to the altitude of 3300m. Before reaching this point, take a beautiful scoop on the left (west) which leads to a flat area (3100m) under the above mentioned rock ridge. Be careful there are big crevasses in this area. A schuss traversing to the right heading northeast leads to Col du Lac (2963m), entrance to Vallon de Chancel. Variants: -The ski lifts of the glacier do not always run (wind, weather...). You can reach Col du Lac from the Col des Ruillans station (3211m) skirting the rocky side which joins the two passes via the glacier (western slope). Walk 2 minutes on the trail towards the ski lifts (south), until taking foot on the glacier and skirting the rocks. Be careful of the crevasses! - You can also enter Vallon du Chancel without the glacier course via the classic route from the top station of Col des Ruillans: put on your skis directly above the station and go around it to the west. Descend the slope completely to the north, passing under the tram cables. Around an altitude of 2950, a sign indicates the separation of the routes Chancel to the left (northwest) and Brêche Pacave (2836m) to the right (northeast). The latter, without difficulty, makes it possible to traverse the rock ledge which borders Vallon de Chancel to the east to reach the Vallons de la Meije route avoiding the initial corridor.

Intermediate part: Vallon de Chancel until P1 (1700m). Under Col du Lac, the dale is very broad and you move completely north towards Evariste Chancel refuge (2506m, high altitude restaurant, terrace, open in winter),  traversing under the rocks of Peyrou d'Aval via sunny northeast facing slopes. The refuge has a lovely view, perched on a rocky spur dominating the Lac de Puy Vachier and the Vallee de La Grave. Variants: there are three variants which avoid the Chancel refuge and pass closer to the Lac de Puy Vachier. They are all more difficult than the classic route: steep slopes, boxed in corridors, risk of making an error in the route. They all end at the spillway of Lac de Puy Vachier (2382m), where they meet the Chancel route by descending Combe de Puy Vachier completely to the north. - the Couloir de la Terrasse (150m, 35 to 40°, northwest exposure, fairly run-out). At the above mentioned Chancel/Pacave junction, continue towards the north while pulling to the right to traverse under the rock band of the Peyrou d'Amont (northwest slope). The corridor entrance is very characteristic, with its U shape, bordered by vertical crags. Be careful of the risk of accumulations during the traverse (slab avalanches) and of falling if there is hard snow. At the end, pull immediately to the right (north) and push-off to reach the lake spillway (2382m). - the Couloir de la Banane  (150m, 35 to 40°, north exposure, fairly run-out). Descend Vallon de Chancel straight down the centre part (northeast) between Col du Lac and Lac de Puy Vachier, until the rock band which dominates the lake. The corridor entrance is located under a snowy dome below, not very visible (locate it during a preliminary descent from Chancel!). Be careful of the risk of falling if there is hard snow. At the end, skirt the lake on the left (north)  pushing off until the spillway (2382m). -The Couloir Dérobé  (100m, 30°, northwest exposure, little run-out). Leave the classic route towards the east during the traverse above the lake in the direction of the Chancel refuge (altitude 25580m approximately). The start of the corridor is hidden by the concavity of the slope and the presence of small rock barriers.

Under the refuge, continue towards the north between small rock barriers (easy) to enter Combe du Rif de Puy Vachier, torrent resulting from the lake of the same name. Traverse this scoop towards the right (northeast) in the direction of Pierre Farabo (2073m) at the forest entrance. Be careful, do not go straight in the forest, the clearings and corridors finish in ice falls! A slight indication (direction sign above the forest) indicates the direction to be followed. To be certain, you can traverse the dale rather high up (2300m) and keep to the right bank.

Once in the forest, a very bumpy and sometimes icy trail (variants above in the forest) leads towards the east as far as the gap under the cables (1900m) and the clearings which dominate the first pylon (P1, 1700m) which serves as an intermediate station for the first section of gondola. Depending on the snow cover and amount of people, you can either go up or continue the descent to La Grave. On crowded mornings it can be a long wait because the gondolas are already full when they arrive, so it is preferable to descend.

Lower part: return P1 -La Grave (1420m). From P1, towards the northeast descend a series of clearings and flat areas intersected with steeper pitches, until over the Abéous torrent (1590m). then carefully descend the steep ramp scraped by skiers (ice, stones) to reach the bridge above the Meije fall. A short ascent (20m) and a flat trail to the northeast quickly leads to Champs de la Lauzette. Depending on the snow cover, descend these fields pulling slightly to the right (completely north) or follow the trail which curves, to reach the bridge (1420m) which makes it possible to cross the Romanche and get to the parking lot and gondola with your skis on your shoulder. 50m before the end of the descent, a hook to the right (northeast) via a broad trail makes it possible to avoid a steep and not very skiable slope. You arrive at the bridge from the northeast.

Steep slope variant: Couloir des Fréaux (800m, 45°, north exposure, run-out) - Under Lac de Puy Vachier Lake continue right on the slope (north) via the torrent until the forest (2200m). Take the first scoop, not very steep at the start, which is inserted in a north-north-west direction between the rocks. Steep and very boxed course, great environment. Rope for useful handrail safety rope in the event of sequence in hard snow or in ice. A second scoop further to the right seems more run-out but it is more difficult due to the presence of ice falls. On the lower part stay on the right bank of the gap of the avalanches to reach the bridge on the Romanche via the forest (trail 1500m to the East) just opposite the village of Fréaux. Car shuttle should be planned. Be careful, this route is run-out and require one degree high of expertise for the skiing, navigation and the choice of snow conditions. The corridor is the place of natural flow for all the sluffs and avalanches from the higher slopes...