III, 41km and 5000m from Les Contamines to the Aiguille du Mid, 3 days. A stunning route with Himalayan-esque views. The route description begins at the Col de Dômes, start/finish point (depending on which way you do the traverse) of the Dômes de Miage Traverse (p.365).
1) Climb the easy snow slope to reach Pointe 3673. Continue eastwards along the ridge over some exposed rocky scrambling straight over the first small summit, and then turn the twin-topped second tower on the right. Rejoin the ridge either via a loose rocky gully, just after the summit of the second tower or (if snow conditions allow) by continuing on the right until after the tower. From here, the ridge begins descending towards the Refuge Durier, which is clearly visible on the Col de Miage.
2) Follow the crest of the ridge in an increasingly exposed position over snow and mixed ground down towards the Col de Miage. The ridge peters out half way between the final twin topped summit and the hut, at which point, make a 30m abseil on the left-hand side of the ridge from a slightly hidden pair of bolts 5m below the crest. The can be split halfway at another two bolts if needs be.
3) Rejoin the ridge crest and follow it down more exposed snow slopes and easy mixed scrambling to reach the tiny Refuge Durier, which is perched spectacularly on the Col de Miage. The hut has a guardian but make sure you book before turning up as he seems to disappear off to the Refuge des Conscrits for some company if there is nobody booked in!
4) Get up nice and early and climb the snow slope above the hut, staying 50m right of the crest of the Bionnassay's south ridge. At around 3600m the ridge flattens out. Move onto the left-hand side of the ridge and continue easily over a small summit to reach a col at the foot of the crux rock step.
5) 3c. Follow a ledge system on the right-hand side of the ridge to reach a corner with a jammed block at the top. Climb the corner (3c) and step out right around the block. Circumnavigate the rest of the rock step on the right to reach the broad snowy ridge which leads to the summit of the Bionnassay. In good conditions reaching the summit should take 3 to 4 hours from the hut.
6) Descend the snowy ridge towards the Col de Bionnassay. The ridge starts out quite wide but it is no exaggeration to call the second half a knife-edge ridge - it is really narrow. How to tackle this will depend on conditions and confidence, but people have used everything from simply walking along it, to one person going on either side with a rope between them, right through to straddling it with a leg either side and shuffling along as if riding a horse!
7) From the Col de Bionnassay, climb up to the Piton des Italiens and follow the increasingly wide and easy ridge to reach the Dôme du Goûter. Follow the Goûter Route (p.340) to the summit of Mont Blanc. © Rockfax
UKC Logbook Description
Miages - Bionnassay - Mont Blanc traverse. Possibly the most enjoyable way up Mt Blanc.
AC guide rates it as AD; Damilano guide grades it III D. Technical difficulties are low, but it's long, long way ... albeit with comfy huts to sleep in.
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