Bourgoin-Jallieu, FRA ·
Nov 7, 2026
Three trails around Bourgoin-Jallieu as night falls over the hills of northern Isère
The Berjatrail Siporex is a twilight trail festival in Bourgoin-Jallieu, organised by CSBJ Athlétisme, with races of 9, 16 and 24 km plus a 9 km walk. Runners set off from the Stade Antonin Berliat in the late afternoon and finish by headlamp, on paths, woodland and hills of northern Isère. The 24 km counts towards the UTMB Index 20K.
The Berjatrail Siporex returns to Bourgoin-Jallieu on Saturday 7 November 2026 for its sixth edition. Organised by the athletics club CSBJ Athlétisme, it starts and finishes at the Stade Antonin Berliat and offers three trails of 9 km (150 m D+), 16 km (300 m D+) and 24 km (480 m D+), along with a timed 9 km walk.
The starts are staggered between 16:45 and 17:30, so every runner heads out in daylight and comes home in the dark: a headlamp and a reflective item are compulsory. The courses link country paths, undergrowth and a pond with the rolling relief of northern Isère. The 24 km, the longest and most demanding format, is an UTMB Index 20K race and requires runners to carry at least 500 ml of water.
The event has grown fast: 821 participants in 2025, then more than 1,400 entries in 2026, with all four formats sold out. It keeps a friendly club spirit, with a race village offering osteopathy and sports massage, a refreshment bar and an optional post race meal, and a clear environmental commitment: bulk food at the aid stations, shared reusable cups, progressive removal of course markings and encouraged carpooling.
Berjatrail 24 km
Berjatrail 16 km
Berjatrail 9 km