This trekking itinerary travels at the feet of the south-west slopes of Pietra Grande, in the Grostè area. After passing Malga Boch the track heads towards the small but charming lake Spinale. Trail No. 331 then crosses over panoramic meadows with wonderful views of the Brenta range. Marmot whistles will accompany trekkers all the way to the arrival at Rifugio Graffer. The departure point is located in Pozza Vecia (a locality about 4 km away from downtown Madonna di Campiglio) where you can leave the car in a free parking area. You can also depart directly from town and climb up with the Spinale cabinway. From the arrival station in a short time you can reach the described track near Malga Boch (trail No. 331).