Hiking (mountain trail, in places narrow and exposed)
Alpine route (equipped or very exposed section, snow field, blocks)
Roya » Refuge de Longon
The trail leaves the hamlet of Roya via the little Sallevieille valley on the GR® 5, overlooked by Mt Mounier, and then reaches the Crousette pass, followed by the Moulines pass, the entrance to the Mercantour national park. Next, it descends to the Portes de Longon valley and arrives at the hut by the same name, which is the stage destination.
From the hamlet, walk downhill to cross the Roya valley (1,465m). The trail enters Mercantour national park. Then follow the right bank of the little Maïris valley. Just after crossing the Roya ledges via an inlet, cross the Sallevielle valley to then follow the left. Walk past a shepherd’s hut (1,955m) in a very barren site and then take a zigzagging path to cross the pastureland in a generally eastward direction, below the Sallevielle ledge, which is crossed on the left. The trail then heads south again, crossing a terrace (spring and rustic shelter for shepherds leaning against the rock ledge west of the trail) to reach the Croussette pass (2,480m). At the pass, take the left-hand path (south-east) that continues the climb on the side of the Mounier (Mount Noir) as far as the Stèle Valette (2,587m). Follow the crest to the north for about 50 metres and then pass over to the eastern slope. Walk past the Démant ridge (2,438m) and then along the mountainside of Mount Démant (north side) and leave the Démant ledge on the left. The trail quickly drops in altitude to arrive at the Refuge pass (2,068m). It then heads eastward, passing along the northern slope of Mount Moulines, heading to the north east and then arriving at the Moulines pass (1,982m). Walk towards the north west and then the north east to cross the Démant stream (1,820m). Follow a carriageway to pass to the left (north) of the Démant rock and cut across the little Combe Maure valley. Leave the track on the left and take a path that is difficult to distinguish. Pass above the hamlet of Vignols and then cross the Gourgette valley (approximately 1,755m), heading up to the Portes de Longon (1,952m). Continue to the east along the right-hand bank of the Longon stream to reach the Roure cowshed or Longon hut at the eastern end of the Longon plateau (1,883m). (Paul Guglielmi, CDRP 06)
Natural and cultural heritage
At the entry to the hamlet of Roya, the trail takes the GR® 5 in a high-alpine environment (between 1,800 and 2,500m in altitude) to the centre of the Mercantour National Park. The rocky Roya ridges rise up in the hollow of the little Mairis valley, where there are still some larch trees growing, and mark the beginning of a very mineral landscape. At the foot of Mount Ferrand to the West, the Roya waterfall hurtles down the limestone rocks and illustrates the omnipresence of water as an erosive factor sculpting the countryside. As is the case everywhere else in Mercantour, there are many streams, making this massif a veritable water tower of the southern Alps. The Crousette pass, the highest point of this stage, transports the hiker back to the XIXth century. In fact, several old ruins can be spotted a few metres away in the direction of the Mounier mountain. It was in 1893 that Raphael Bischoffsheim, an astronomy enthusiast, established an annex to the observatory in Nice there. His aim was to measure the speed of light between the two sites using skilful calculations. The building was converted into a hut by the French Alpine Club in 1936 and then abandoned owing to the lack of water and the overly harsh weather conditions. The stela erected lower down in memory of Lieutenant Valette-Viallon, who died in 1936 further down the pass, reminds us of the risks presented by this type of geological formation (rocky ridges and straight shale slopes). The Mounier summit or “Mont Noir” (black mountain), a geomorphological curiosity (hanging syncline) characterised by the blackish colour of its rock and its merciless aridity, offers a unique panoramic viewpoint. Only the Moulines pass, used as summer pastureland for cattle, foretells a return to more gentle terrain. Further downhill, the Vignols valley, a picturesque hamlet in a pastoral setting with a particularly rich religious heritage, was selected in 1993 by the Mercantour National Park as a reintroduction location for the bearded vulture. This large predator with a wingspan of 2m 80 is known for its penchant for bones (which it breaks by dropping them from high altitudes over scree) and the tendons of its carrion. The GR® trail then reaches the Longon Hut on the mountainside, an old cowshed (which explains its long shape) at the entrance to the Mercantour park. This last high-alpine stage marks the transition between the hostile, high-altitude mineral world of this extremity of the Mercantour massif and the lush valleys where farming activity abounds. (Sara Zeidler, Gilles Chappaz, Grande Traversée des Alpes)