From the top station of the Index telesiege, follow the obvious path heading left (west) to pass below the SE Ridge of the Aiguille de l'Index. After 5-10 min, descend steeply on an eroded section of the trail for about 50m and then continue traversing over scree on a mostly level path until below an obvious gully which leads up to the right of the Glière's south ridge. Climb this gully, keeping to the right side (faint path) initially to avoid loose rock in the bed. When the gully narrows, move left and scramble up over easy, solid rock to reach the start of the route. The start is easily identified by a 60m left facing corner/chimney which leads up to the crest of the ridge. There are 2 fixed pins at the start of the pitch from which to belay.
The route consists of about 14 pitches, although some are easy and could be easily linked or climbed with a running belay. Below is a description of the route as we climbed it on August 12, 2004. Ratings for each pitch are from the French guidebook "Les Aiguilles Rouges: Escalade au soleil" by Dulac and Perroux, which I found to be very accurate. The climb involves a vertical ascent of 400m and takes 3-5 hours.
Pitch 1 (4c) -- Climb the prominent left-facing flake above the belay either directly or by climbing up slighly to the right and then moving left to the flake. Above the flake, continue up a slab and left facing corner on thin holds passing a piton. There are good opportunities to place gear in the corner to the right. A last bit of steep climbing on big jugs in a chimney leads to a belay at a bolt on the left. There are flakes nearby which can also be used to belay.
Pitch 2 (4a) -- Continue up the gully/right-facing corner above to reach the crest of the ridge. The climbing on this pitch easy with lots of big holds.
Pitch 3 (3c+) -- Traverse along the crest of the ridge, then move slightly down and right to climb a weakness. After a few meters, traverse back left, and then finally up and right to a belay under a huge right-facing corner. This pitch is easy, but a bit exposed. Watch for rope-drag with all the moving back and forth.
Pitch 4 (5a) -- One of the crux pitches. Climb the right-facing corner, or avoid the first few moves on easier holds to the right. There are 3 or 4 pitons on this pitch and they can be backed up with small stoppers and cams. The climbing is very well protected. Belay on a small ledge 2/3 of the way up the corner at a pair of pitons.
Ptich 5 (4c+) -- Continue climbing the corner past more pitons, then move around left and regain the ridge crest.
Pitch 6 (Walk) -- Easy scrambling leads to the next step on the ridge at a steep wall split by two vertical cracks.
Pitch 7 (4b) -- Climb the crack on the right, then move around left (exposed) and continue up a chimney to a belay at a huge block, just before a very sharp and exposed-looking section of the ridge. A bolt protects the opening moves to the crack and the crack takes small stoppers (bomber).
Pitch 8 (4c+) -- Make a committing move up the sharp section of the ridge on a small foothold with no hands to reach a solid horizonal crack. A small cam can be placed at the far left side of the crack. Move right and begin traversing the "Rasoir" or "Razor," a very sharp fin of rock with good hands and smearing (see photo). There is one piton and a fixed sling for protection (the sling is actually threaded through a hole in the razor. Belay at bolts after completing the traverse.
Pitch 9 (Walk) -- Continue over very easy ground to a notch in the ridge, below the next steep section. A path can be seen descending down right from the notch and can probably be used to escape the route.
Pitch 10 (3) -- Take the path of least resistance up and right to avoid some 5b climbing on the ridge itself. Very easy terrain can be found by traversing far right to a gully, although this looks to be quite loose. Belay from any solid block.
Pitch 11 (3) -- Continue climbing up and right to reach a faint and eroded climbers' path which leads up to a deep chimney/gully. Climb up the gully to arrive on a sharp crest just below the Chapelle.
Pitch 12 (3) -- Traverse left on the crest, then descend a few meters and continue right to the base of the Chapelle. Note that the final two pitches to the summit can be by-passed on the left to arrive easily at the descent path below the steep west face of the Chapelle.
Pitch 13 (5a) -- Climb directly towards the summit of the Chapelle on a steep slab passing flakes. This pitch is a bit run-out and tricky to protect. Sling the summit block and continue along the crest, descending slightly, to some fixed slings below the final tower (Clocher).
Pitch 14 (6a or 5a A0) -- Make a committing and unprotected move up to a piton and then traverse left past another piton to a fixed sling around a large horn. The section is very steep with few holds and some aid may be required. Climb onto the top of the horn and continue easily to the fixed anchor on the summit (many bolts).
Descent -- Make one rappel of 20m down the steep west face of the summit tower. This is a bit tricky getting started. Unrope and follow the obvious path (marked with a few cairns) on the southeast flank of the Glière towards the Col de l'Index. The path is straightforward with a few ups and downs. From the Col, descend the gully as for the Aiguille de l'Index, or continue following cairns to the southeast to reach a rappel anchor, where one 30m rappel leads to easy ground and the cable car.
Rope -- A single 45m rope is sufficient
Rock Protection -- There are many pitons on the route and many people take only a few quickdraws. However, I recommend one set of stoppers, a few cams (BD #0.4 - #2), and a few long slings
Helmet -- Absolutely essential
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