The Gorges de Trévans are one of the most spectacular natural sites in the Alpes-de-Haute-Provence — and one of the least known, partly because they are not, hydrologically, in the Verdon. They are carved by the Estoublaïsse, a tributary of the Asse, in the Montdenier massif, between Castellane and Digne-les-Bains. We say so right away rather than leave the ambiguity hanging: here is what really links them — and does not link them — to the Verdon territory.
Verified on 20 August 2026 with the ONF (manager of the reserve), the Digne-les-Bains Tourist Office and the Parc naturel régional du Verdon.
The essentials
| Distance | 10 to 12.5 km depending on the source |
| Elevation gain | 540 to 600 m of elevation gain |
| Duration | ~4h15 to 4h30 |
| Difficulty | Moderate (T2) |
| Type | Loop |
| Start | Gorges de Trévans car park (606 m), Estoublon |
| Highlight | Viewpoint (976 m), Montdenier massif |
Trévans and the Verdon: a geography to clarify
This is the most important point of this fact-sheet, and we document it rather than pass over it in silence. The Gorges de Trévans lie in the Asse basin (via its tributary the Estoublaïsse), not in the Verdon basin — a neighbouring valley, north of Castellane. Administratively, they extend over four communes: Beynes, Estoublon, Majastres and Senez.
The link with the Verdon has changed recently: when the reserve was created (2021), only Majastres belonged to the perimeter of the Parc naturel régional du Verdon. With the park’s new 2025-2040 charter (decree no. 2025-390 of 28 April 2025), Estoublon and Senez joined the Verdon PNR; only Beynes remains outside. Three of the reserve’s four communes are therefore now within the park’s administrative perimeter — a recent status, not a long-standing fact.
Practical consequence: the competent tourist office is not the Castellane-Verdon one, but the Provence Alpes Tourist Office (Digne-les-Bains), since Estoublon belongs to the Provence Alpes Agglomération inter-municipal authority.
It is not a regional nature reserve
Another useful clarification: the Gorges de Trévans form an integral biological reserve (RBI), a state protection category in state-owned forest, managed by the ONF — and not a regional nature reserve (a category that falls under the Region). It was created by order of 12 February 2021, over 1,205.55 ha, in the state forests of Montdenier and Suy.
It protects a remarkable site on three counts:
- Geological: cliffs, gorges, limestone pavements (lapiaz), faults and caves in Jurassic limestone; the site lies within the perimeter of the Haute-Provence UNESCO Global Geopark.
- Floristic: 610 vascular plant species recorded by the Conservatoire botanique national alpin, including two protected ones (Verdon spleenwort — doradille du Verdon — and Bertoloni’s columbine — ancolie de Bertoloni).
- Faunal: more than 100 breeding bird species, protected bats, a permanent presence of the wolf (ONF).
The route
From the Gorges de Trévans car park (606 m) in Estoublon, the trail waymarked in yellow climbs to the viewpoint (976 m), a vantage point over the deep gorges and the Montdenier massif. An airy cabled passage is signposted about a hundred metres after the viewpoint — judged harmless in fine weather and without snow, but to be taken seriously in bad weather.
Strict regulations, as is often the case in a biological reserve: mountain biking is only allowed on forest roads, and canyoning is forbidden (official ONF fact-sheet). Overnight parking (22:00-06:00) is said to be regulated by an order of 2020 — to be confirmed on site. On the other hand, no specific rule on dogs on a lead or on bivouacking was found on the official fact-sheet: we do not invent one, so check the signs on site.
Practical access
From Digne-les-Bains: N85 towards Barrême/Nice, then at Châteauredon the D907 towards Mézel/Moustiers, then at Estoublon the D667 for 5 km to the car park — about 32 km in all. From Castellane, the road first leads to Barrême (24 km via the D4085); beyond that, the exact distance to the Estoublon car park could not be checked against a reliable source — we prefer not to put forward an unsourced composite figure.
What is still missing
We would rather say so: the full text of the order creating the RBI (paywalled) was not consulted; the exact regulations on dogs and bivouacking were not found on the official fact-sheet; the precise road distance between Barrême and the Estoublon car park was not checked; finally, a secondary source mentions membership of the Réserve naturelle géologique de Haute-Provence, but Trévans does not appear by name in the list of its 18 sites — so we do not assert it. These fields will be completed as soon as a reliable source specifies them.
Sources
Data cross-checked and verified on 2026-08-20: ONF (official fact-sheet of the integral biological reserve of the Gorges de Trévans), toporandosmontagne.com, Provence Alpes / Digne-les-Bains tourist office (dignelesbains-tourisme.com), Visorando, AllTrails (via search), Wikipedia FR (Parc naturel régional du Verdon), Légifrance (decree no. 2025-390 of 28 April 2025), Provence Alpes Agglomération. Discrepancies retained and flagged above. No data invented: a missing field is flagged as such.