After reaching the village of Pillaz, either on foot or by car from the village of Fontainemore, following trail marker No. 2, follow the route of the cross-country road that, training in the woods, enters the Vallone del Vargno.
The road runs straight along the wooded slope until it flanks the Pacoulla River. After a few steep hairpin bends, it crosses the little bridge below the Mattà mountain pasture (1677 m). Just past the building, take the path to your left, just before the Vargno basin. Here begins the beautiful path, paved in places, that leads into the Mont Mars Nature Reserve.
Continue observing the Vargno lake on your right and, past a glacial step characterized by scree, you reach the beautiful basin of lakes including Lè Lounc and Lé di Barma (2020 m). Skirting the Barma retreat, you finally reach the Colle Barma, after walking the last few hairpins bends in about 20 minutes.