The walk up
From Fionnay the path climbs about 800 metres over roughly 9 km, and takes around two hours at a steady pace. The trailhead is directly opposite the car park, on the left as you arrive. It is a sustained climb rather than a technical one — no exposure, no scrambling — and it ends at the Lac de Louvie with the hut at 2,207 metres just above it.
Parking and getting there
Park at Fionnay (1948 Bagnes), opposite the dormitory building; the trail starts across the road. Without a car, Le Châble is the rail head, with postal buses up the valley. The hut also sits on the Chamonix–Zermatt Walker's Haute Route, so it doubles as a stage rather than only an out-and-back.
With a dog, with a child
Dogs are allowed but must be on a lead — this is a protected reserve, and the ibex, chamois and marmots are the reason to come. For children, the honest answer is that 800 metres of ascent needs legs that have done it before; there is no lift and no shortcut. Older children who hike will be fine, and will see wildlife.
Staying the night
The cabane has dormitories and a warden in season, and the lake at dusk is the argument for not turning round at the top. Book ahead, and check the guarded dates before setting off.
