NB: the route described below was completed on snowshoes.
(S/E) In the centre of the village of La Pesse, near the church, head east towards Crêt de Chalam.
Pass a small shed, then take the purple-marked snowshoe route on the right.
(1) At Col du Nerbier, you will already be able to see Crêt de Chalam.
You then descend into a magnificent mini valley to arrive at a place called "Le Berbois".
If you feel like it, you can stop at this stopover lodge (GTJ) for a drink or a snack.
Continuing south, you will pass the car park and arrive at Borne au Lion.
(2) At Borne au Lion, take the path on the right (this is the GR®9) and then, 300 metres further on, turn left (leaving the GR®9) onto the well-marked path towards Crêt de Chalam.
You will arrive at a flat area below the final climb that will take you to the summit.
On the final climb, be very careful not to slip to the right (east) as there is a rocky outcrop just below. Keep well to the left of the path (to the left of the steps, if still visible).
(3) From Crêt de Chalam, you can already see the Valserine valley and the high Jura mountain range (Reculet, Montrond, La Dole and its white ball).
Several orientation tables will help you get your bearings.
There is even a wooden bench...
Descend carefully to the north (stay to the left) to reach the Col de l'Encoche.
Take a path on the right that goes around a mountain.
Cross a stream (barely visible if there is heavy snowfall) to reach a very open area at the Borne au Lion, which you already passed on the way there.
(2) From there, follow the route in the opposite direction to the start car park (S/E).