A big day route in the big mountains of the Écrins national park, A classic that can be done as an overnight in winter or in a day in spring, or as a round trip from the glacier Blanc, just remember to bring your big legs!
There are a few options for when and how you do this route:
1) In winter they shut the road to Ailefroide at Pelvoux, you can skin up the road and spend the night in the winter room at the Refuge Cézanne, from there you can climb up the route and ski back down to Pelvoux the next day. I did it this way as it was a poor snow year and wanted to make sure there was snow top to bottom by climbing it. So it is how it is described here. From leaving the refuge head towards the glacier Noir and then cross it climbing on the the moraine ridge. Climb up the ridge (or the gully behind it) until you get to the Ravin de l’Armaille then turn north and climb it. It mixes between wide open slopes and small gullies that are tight and closed in by rocks. Near the top is a very tight section (the GPX is a rough version as I didn’t use my phone to save battery).
2) In the late spring they open the spring parking which isn’t far from the refuge so you can do it in a day.
3) As a round trip you can climb to the glacier Blanc refuge, from there you climb the glacier Blanc and then climb to the col de la grande Sagne from the north side then ski down the south.
Ski the south couloir back down, its a long ski but lots of islands of safety to have a break, just be aware of stuff coming off the rocks around you as they heat up. Down to the valley floor you can stay in the gully left of the moraine ridge (often good snow) or ski over the ridge and back on the glacier noir. At some point you need to cross the glacier and head back to the refuge, from there it is a pole/skin back to the spring parking or where the road steepens to allow you to ski back to Pelvoux.