Runners start and finish at the Popaghja forest house in the Valdu Niellu forest, Niolu region. Restonica Trail Blanc is a chip-timed winter trail event offering an 18 km race, an 8 km initiation race, and a walk. The day's events support the Marie Do association. The 8 km race follows the same route as the walk, accommodating both runners and those seeking a shorter forest outing.
The 18 km loop covers 625 m of elevation gain, crossing forest and ridges through larch and birch stands. It ascends first along the Orso Longu ridge towards Lake Ninu, gaining 250 m in 1.8 km. A ridge path is then followed for nearly 4 km before merging with the GR20. After a gradual 2 km descent, a second significant climb heads towards Bocca A Manuella and Capu di Verghju, adding another 250 m over 2 km. From this higher elevation, participants can view the Gulf of Porto to the west and the Niolu valley and its dam lake to the east. The day concludes with a Spuntinu, the communal post-race meal.