Location ✦ Neste d'Oô valley
Region ✦ Haute-Garonne
Country ✦ France
Max altitude ✦ 2670m
Distance ✦ 21.5km
Vertical drop ✦ 1450m
Difficulty ✦ E3 / T3 / R2
Duration ✦ 7h to 8h (round trip)
Interest ✦ ★★
Access to the place
Map & topo
Hiking to the start 2'
Leave the parking lot to the south, cross the Médassoles stream to find the track leading up to Lac d'Oô, the starting point for the ascent.
Course 3h30 à 4h30
This is a round trip from the Granges d'Astau to the Portillon refuge. A long ascent in successive stages: Lac d'Oô then Col d'Espingo and Lac Saussat, Coume de l'Abesque before reaching the upper part of the Neste d'Oô valley and Lac du Portillon at 2500m. No technical difficulties, but a significant altitude difference to swallow, especially if you're a bit heavy for a few days at altitude. While the first part of the hike is on the GR10 route, the paths afterwards are very well marked, with numerous cairns along the way to Lac du Portillon.
Bivouacs can be set up just about anywhere around the refuges, including on the shores of Lac du Portillon, where you can leave your tent for the day and explore the surrounding area. The managers of the Portillon refuge are very welcoming, and there's an off-bag room for lunch or dinner.
Part 1: Lac d'Oô (1500m, 50' to 1h)
Follow the wide GR10 trail, which climbs gently and then more steeply to reach the 1st level. A flat spot, a slight descent and you're below the Lac d'Oô dam. Leave the refuge on your right and continue along the left-hand path that crosses the dam.
Part 2: Col d'Espingo (1967m, 1h15' to 1h30')
The path quickly rises above Lac d'Oô, in the undergrowth, skirting it on the eastern slopes. A superb waterfall flows into the lake to the south. The route then becomes steeper, with numerous switchbacks, before dropping southwards and finishing on a small grassy combe. Leave the fork on the left of the GR10, which heads towards Superbagnères, and continue over the small Col d'Espingo, which opens onto a new area in the shape of a green cirque. In the background and above, you can now see the Tusse de Montarqué and the Spijéoles peak. A splendid natural setting. Coffee break at the refuge de l'Espingo, just below the lake.
Part 3: Coume de l'Abesque (2100m) and Lac du Portillon (2570m, 1h45' to 2h)
Descend the high valley to the south, cross the Neste d'Oô then follow Lac Saussat to the right before climbing a little to reach Coume de l'Abesque, where a waterfall starts. From here, the path bends to the east to climb steeply up a first promontory, then continues to climb steadily until it reaches the upper plateau via a small rocky couloir. At 2500m, the rest of the climb is on large slabs to reach the Portillon hut at the end, after a final mini-steep climb, facing the lake and its dam.
Return to Granges d'Astau via the ascent trail. Nearly 1500m of negative altitude difference to negotiate, with several steep slopes on rocky paths. Fortunately, we can take a coffee break at the Espingo refuge to cut the journey in half.