Park at the Saint-Bruno bridge on the D520B between Saint-Pierre-de-Chartreuse and Saint-Laurent-du-Pont. There are only a few parking spaces upstream and downstream from the bridge.
(S/E) The trail starts just downstream from the bridge. It is well marked (blue fish). The trail follows the course of the Guiers Mort to the Pic de l'Oeillette. Be careful, there are a few tricky passages among large boulders.
After these passages, you will come to a wider path.
(1) Turn left. Please note that the trail has changed from the map; this fork corresponds to the fork shown a little higher up on the map. I have kept the track made with my GPS.
(2) Do not take the ford, but continue on the path to the right (marker: Blue Fish).
Personally, I preferred to go to a small beach near the last bridge.
(3) The path continues a little further after the bridge.
The return journey is along the same route as the outward journey.
(1) Be careful not to miss the fork on the right. Arrival at the Saint-Bruno Bridge (S/E).
The trail is currently closed for works from 14 August to 30 November 2023 (the "blasting" sign is very dissuasive).