Climb up to the Hautacam ski resort. At the Col de Tramassel, large car park, take the track on the right, heading south-west, which leads to the Courade de Mauscasau (car park), and continue along the track that branches off to the left until you reach the Col de Moulata car park. This last section of the track is in poor condition. Drive very slowly. For low-clearance vehicles, it is best to park either at the Col de Tramassel car park or at Courade de Maucasau. In both cases, this will add to the length of the hike: 3.2 km or 2 km there and back.
(S/E) At the end of the Moulata car park, take the slightly downhill path on the right (signposted). This path leads to Lac de Bassias via the Hourquette d'Ouscouaou. Follow it until the junction that leads to the latter.
(1) Take the path that descends to the right until you reach the path that leads to the Cabane de Picourlet.
(2) Leave the path that descends to Lac d'Isaby on your right and continue left on the trail that leads to the Cabane de Picourlet.
(3) Follow the well-marked trail that leaves after the hut, heading south, then sloping south-east. The path, which is still well marked, arrives at Lac dets Plagnous.
(4) After a well-deserved break, return to the car park by following the same path in reverse (S/E).