Park in the car park of the Col de Porte.
(S/F) Take the road to the Charmant Som cottages (D57E) following north-west then north. In winter the road is closed to traffic.
(1) Shortly before the Orgeval chapel, leave the road and turn left (south-west) onto the Tour de Chartreuse GRP along the ridges (Yellow and Red markings).
(2) Pass above the (closed) Charmant Som chairlift and continue over the ridges.
(3) Pass Mont Fromage and continue on the ridges.
(4) At the crossroads, leave the ridge (that would take us to the Pinéa) and turn left towards the Col de Porte. Shortly after, the road makes a hairpin left turn. Continue, passing a path on the right and follow the path that goes down gently through the woods to the Col de Porte (S/F).