Pics d'Ayous and Pic de Larry circular via the Vallon d'Aas de Bielle

From Laruns, head towards Spain via the Col du Pourtalet. After the hamlet of Gabas (commune of Laruns), at a hairpin bend with a small car park on the left, turn right towards Lac de Bious-Artigues (road closed in winter, which explains the presence of the "No Vehicles" sign, which can be confusing).
There are two car parks available. The first is on the edge of Lac de Bious-Artigues and the other is a little further down before you reach the lake.
Leave early, otherwise you will have to park in the "lower" car park, which means an extra thirty minutes' walk.

(S/E) From the car park (altitude 1304), head to the foot of the dam at the western end of Lac de Bious-Artigues, taking a section of^{the GR®10}and^GR®108trails, then one of the many footpaths.
Continue for a few dozen metres and follow the traffic on the arch dam itself (not visible from the car park).
Continue along the path that goes around the lake in an anti-clockwise direction.

(1) At the fork, take the path on the right, which climbs rapidly into the forest along the Ruisseau d'Arec d'Aas stream. This is where the Vallon d'Aas de Bielle valley begins.
It is sometimes described as a hidden valley or secret valley, in contrast to the classic, highly frequented Ayous lakes route.
The trail encounters several side forks at an elevation of 1,491 metres; continue straight ahead.
The trail climbs a little over 200 metres before leaving the shaded part of the valley.
The landscape changes completely. The view is wide open as you approach the first hut in the Vallon d'Aas.
On the right are the south-facing slopes of Soum d'Aas (2427 metres), which are quite arid with low vegetation and stony ground. On the left below is the bottom of the valley, with Arrec d'Aas and a metal cuyalas (enclosure) for keeping sheep at night.

(2) A short stop at the Vallon d'Aas pastoral hut allows for a mini-break (about 1 hour after departure).
Continue straight ahead uphill. The path continues to climb steeply.
At an altitude of 1,825 metres, cross the main stream of the Arrec d'Aas for the first time.
(On the other bank, you can leave the trail and approach the next ravine, which is not recommended to cross here).
Follow the stream to reach the second crossing, here near a secondary tributary of the main stream, at 1930 m.
The ruins of a metal cuyalas show the force of the snow slides in winter.
From there, the path, which generally followed a west-southwest direction, turns southwest, running under the north-south ridge starting from Soum d'Aas and joining Pic d'Ayous.
Reach the Col d'Aas de Bielle (elevation 2098 m).

(3) The pass provides a route for^{the GR®} 10 from the Chemin de la Mâture and La Baigt de Saint-Cours in the Upper Aspe Valley to Lac de Bious-Artigues in the Upper Ossau Valley.
The ridge leading to Pic d'Ayous is only accessible by climbing.
Descend to the south-west towards Baigt de Saint-Cours, taking a fairly modest but well-marked path with a 50 m drop.
The path then climbs between rocky outcrops in a small valley (still snow-covered at the end of May 2022 but perfectly passable without equipment).
At an altitude of 2,212 metres, you will reach the small pass between Col d'Ayous and Pic d'Ayous (also still covered in persistent snow at the end of May 2022, but perfectly passable without equipment, except for a pair of walking sticks as both sides are exposed).

(4) Take the ridge due east to reach Pic d'Ayous (elevation 2288).
(You can easily walk along the ridge to the north to elevation 2264, overlooking the Col d'Aas de Bielle, which you passed earlier).
After spending the necessary time at the summit (see paragraph "During the hike or nearby" below), turn back to the small pass you have already passed.

(4) Continue straight ahead, descending and staying on the ridge, heading south-west. Reach the Col d'Ayous at an altitude of 2188 metres.

(6) A marker post marks the pass, as well as the^GR®10trail markers, which pass through here (to the right towards Chemin de la Mâture, to the left towards the Ayous Lakes).
Continue straight ahead, slightly below and to the left of the ridge, still heading southwest, then quickly turn south.
Follow the gentle ridge line.
400 m after the pass, you will come to a rocky outcrop on the ridge.

(7) Do not cross it, but descend to the right into a small hanging valley, on a narrow, unexposed path.
Once at the bottom of the valley, look for the best route, depending on the presence of late snow, to climb up on the left onto the ridge leading to Pic de Larry at an altitude of 2,337 metres (the destination of the hike).
There are no exposed passages, as the ridge is well rounded.

(8) Turn back for the descent until you reach the Col d'Ayous ridge at the rock mass.
As soon as possible, turn right into the basin below the Col d'Ayous.
Depending on the season, cross a small snowfield or a network of small meltwater streams (at the end of summer, everything is dry).
Join the^GR®10, which descends towards Lac Gentau. Further down, you will come to a fork in the path that you must not miss.

(9) The^GR®10continues along the slightly descending contour line. Leave the southbound trail, which descends much more steeply towards the refuge.
After a few hairpin bends, you will reach Lac Gentau at an altitude of 1,947 metres and a very obvious fork in the path.

(10) Turn left onto the^GR®10, where the red and white markings resume. Leave Lac du Miey on your right. Descend the Cascade du Miey passage until you reach Lac Roumassot and the pastoral hut at 1,850 metres.

(11) Continue on the^GR®10until you reach the Col Long d'Ayous clearing. Instead of continuing on the^GR®10, leave the trail on the left and head towards the (main) Cabane du Col Long d'Ayous at 1,698 m.

(12) Continue down the valley towards the forest.
Enter the forest. Pass the spring at 1,650 m on your left.
Continue on a gentle descent through the forest for just over a kilometre and 240 m of elevation loss.
Reach the first crossroads with a track around the lake and continue to the left. Reach a second crossroads with the main track around Lake Bious-Artigues.

(13) Turn left to walk around the lake in a clockwise direction. Return to the crossroads at the lake shore.

(1) Continue straight ahead in the opposite direction to the outward journey, cross the dam and then return to the car park (S/E).

The description is based on a solo "summer" hike in spring (end of May 2022). However, there are still a few snowfields to cross on the route, but they can be crossed without equipment.
Even though half of the route is unmarked, the paths are clearly visible. You can do this route with just a map; a GPS or the Visorando app on your smartphone are useful but not essential.
The idea is to get away from the crowds by taking a hidden route.
However, this route is only suitable for those wishing to climb Pic d'Ayous and/or Larry, not for those wishing to reach the Ayous Refuge alone, as it adds 70% to the elevation gain!

Parking at the start
The D231 road leading to the Lac de Bious-Artigues car parks is in good condition but not very wide. It is blocked by numerous transverse gutters, which must be crossed slowly but without difficulty.
In spring, there is no attendant and no charge. Once you arrive at the^first car park at Bious-Oumette, there is no way of knowing whether there are spaces available at the second car park at Bious-Artigues, so many vehicles make the return trip for nothing. Checking these trips back and forth before heading to the^second car park will save you 15 minutes or more in the car and allow you to make the most of the time by walking from the^first car park!

Time indicated
I completed this route in just under 7 hours, including breaks and a picnic, leaving the car park at 9.45am. This is a fairly short time. Allow between 7.5 and 8.5 hours.

Difficulty
Classified as a medium hike; the trails are all visible and sometimes marked^GR®10. The destinations (passes, peaks, lakes) are visible from afar. There are no exposed sections and the slopes are reasonable.
However, you need to be fit to cover a distance of nearly 16 km and a moderate elevation gain of 1,170 m.
The IBP Index (automatic route difficulty assessment system), a partner of the FFRandonnée, is 135 HKG, which corresponds to a Medium route for a hiker with a high level of physical fitness.

Water points
There are no drinking water points along the route.
There is a drinking water source at the Refuge d'Ayous, 450 m from the WP (9).
Springs, lakes, rivers and runoff water are not guaranteed to be drinkable due to grazing livestock.
Allow 1.5 litres per person.

Shelter

• The Cabane d'Aas de Bielle has a tiny section that is open all year round and can temporarily accommodate 6 people standing inside, in case of a storm, for example.
• The Refuge d'Ayous, 450 m from the WP (9), can accommodate many hikers all year round, day and night. For a night during the guarding period (late May to early October), except in emergencies, you must book well in advance to secure one of the 47 places. Outside the guarding season, there are 12 places, which are sometimes in high demand as the place is very popular.
• The Cabane du Col Long d'Ayous can accommodate around four people all year round, day and night.
• However, in an emergency, you can also take shelter along the walls of any of the huts mentioned above.

Equipment
Bring the usual equipment for hiking in the high mountains in summer: hiking boots, suitable clothing, rainwear, sunglasses, water, food, survival blanket, knife, compass, map, whistle, sun cream, lip balm and walking sticks if necessary. A GPS or the Visorando app on your smartphone can complete your equipment to make your hike truly safe.

Visitor numbers
In summer, the route is very busy from (S) to (1).
Beyond that and up to the Ayous Small Pass (4), you may encounter a few rare hikers.
Between (4) and (6), the number of visitors increases significantly.
Between (6) and (7), you generally won't encounter anyone.
Between (6) and :11::, it is once again very busy, especially on sunny late afternoons at weekends or during school holidays.
Between (11) and (1), you can enjoy the tranquillity of solo hiking.
The vast majority of this route is therefore in an area with little or no traffic.
Whatever the season, do not forget to inform your friends and family of your exact route and notify them of any changes by text message or telephone.

Météo-France mountain bulletin
Check the weather forecast.

If you notice any errors in the signposting or place names on your route or on the map you are using, you can become a contributor and report them:
- marking errors, safety issues, conflicts of use, environment, etc.: click here
- mapping errors, place names, etc.: click here

Lake Bious-Artigues
This is an artificial lake with a thin arch dam, built between 1953 and 1957. With a height of 50 m, a drop of 285 m and a capacity of 5.1 million m³, it engulfed part of the Bious-Artigues plateau and replaced it with the lake.
The dam and hydroelectric power station are owned by SHEM (Société Hydroélectrique du Midi).
Bious means "water hole" in Gascon. Artigues means "places of land clearing in the Middle Ages, which created new clearings".
Source: Wikipedia

(2) Cabane du Vallon d'Aas de Bielle (1,668 m)
A charming pastoral hut, nestled in a rock hollow, with a terrace, table and benches. It is used by shepherds in summer. A small open area can serve as a shelter for six people standing up in case of a storm.

(3) Col d'Aas de Bielle (2,098 m)
The stream flowing on the upper side of the Aspe valley is the Baigt de Saint-Cours. Baigt, pronounced Batch, means valley in Gascon.

(6) Col d'Ayous (2188 m)
It is not uncommon to encounter quite a few people here on fine weekends in May, as it is a crossroads for several trails, including the^GR®10, which you will rejoin here.

(8) Pic de Larry (2337 m)
Practically the same view of the surrounding peaks as from Pic d'Ayous, but from a different angle, which is very interesting.
View of the Pic du Midi d'Ossau, the Ayous Lakes, and in particular Lake Bersau (2,100 m). At the end of May 2022, the latter is still partially frozen.
The setting is magical!
There is no one on this summit, while many hikers crowd the Col and Pic d'Ayous.
See also the winter route on the Pic de Larry, a hike by the same author, MCTOUL.

(10) Lac Gentau (1950 m)
From there, on weekends and school holidays, if the weather is fine, from May onwards, there is a rush of walkers and hikers coming from the Lac de Bious-Artigues car park.

Between (10) and (11) Miey Waterfall.
Don't miss taking a few photos of this magnificent waterfall! It is the only one of its kind on the route.

(11) Pastoral hut at Lac de Roumassot (1,850 m).
Renovated in 2021, sheep's cheese is made here in the summer.
It replaced the old stone Roumassot Hut, which was open all year round.

(12) Cabane du Col Long d'Ayous (1698 m)
Known as "d'En-Bas" (down) to differentiate it from the nearby hut known as "d'En-Haut" (up). This hut has three small areas: a fireplace, storage space and a sleeping area. Capacity: four people. Rustic condition.

Between (12) and ::12: Crossing the forest.
This alternative trail is not really a shortcut in terms of distance or time. However, it offers very refreshing undergrowth landscapes and, above all, is completely uncrowded, unlike the classic^GR®10trail and its concrete sections, which are very busy.

(13) Lake Bious-Artigues.
Going around the lake clockwise on the left adds a little to the length of the walk, but allows you to continue hiking in solitude, rather than in the crowds on the^GR®10.