From Flumet, take the D1212 towards Ugine, then the D113 to Saint-Nicolas-la-Chapelle. Continue on the road that climbs to Le Plan, then to the hamlet of Chaucisse. Car park at the entrance to the village.
(S/E) Follow the road uphill, pass two hairpin bends and, at the house on the left, continue along the mountain track to the next right-hand bend.
(1) Leave the track and continue along the path opposite. Ignore a turn-off on the right, enter the woods and descend to the Ruisseau du Grand Nant stream. Ford the stream and immediately take the path that climbs to the right through the undergrowth. Then cross a small alpine pasture (close the gates behind you) and pass through a small patch of woods. You will see an alpine hut about a hundred metres above you.
(2) Just after leaving the woods, turn right onto a barely visible track, which you can make out thanks to the flat area it forms, and leave the path that continues to a "muddy patch" about 50 metres further on. Continue along this track until you reach the clearly visible cross-path above that leads to the hut.
(3) Follow this path to the left, which runs along the base of Le Treu, until you reach a fork.
(4) Continue straight ahead. The path joins a track which you should follow to the Chalet des Avenières (orientation table).
(5) Take the path that climbs to the right, cross a wood and a meadow to reach the foot of Le Treu. Begin a steady climb which, via numerous small hairpin bends, leads to the summit of Le Treu.
(6) After enjoying the view, continue downhill on the other side until you reach a cross-path.
(7) Take a small path on the right along the mountainside and rejoin the route you took at the foot of Le Treu.
(4) Continue downhill along the same path and reach the hamlet of Chaussisse (S/E).