Start from the Pla de la Lau car park.
(S/E) Head south and take a wide, flat forest track. After a wide open area, the path narrows under light woodland cover. Follow the signposts for the Refuge des Estagnous and Mont Valier. Stay on the left bank of the stream.
(1) At a fork in the road, turn left towards the Refuge des Estagnous and Mont Valier (ignore the path going straight up to Barlonguère). Cross the Riberot via two successive footbridges. The path then climbs up the right bank of the stream and crosses a few clearings alternating with wooded areas.
(2) At the junction just past the Tute de l'Ours, take the path on the right and cross the Riberot stream via a footbridge. Now follow the left bank of the stream up to the Nerech waterfall.
(3) Cross the stream again via a footbridge. The slope becomes steeper at first: climb up a few switchbacks. The slope then levels out somewhat. You will arrive at the Cabane de Caussis.
(4) Just past the hut, continue leftwards uphill towards the Refuge des Estagnous (ignore the path on the right towards the Étang Rond). The path climbs steadily, heading east-southeast, to reach the Refuge des Estagnous.
(5) The path continues eastwards, initially with a gentle climb. The gradient then becomes steeper and handrails provide safety on the trickiest sections. You reach the Col de Faustin.
(6) Head north-east and climb up relatively easy slopes. This will take you to the summit.
(7) Mont Valier. Return via the same route to the car park (S/E).

. The descent was a bit long in these conditions (4h15 from the refuge, including a 20-minute break).