Two approaches to Bocchetta dei Tre Sassi are possible. Both start from Passo Campo Carlo Magno north of Madonna di Campiglio:
- Passo Grostè
Take the cablecar to Passo Grostè. Either take Ferrata Gustavo Vidi (390) to climb towards the bocchetta or descend to Rifugio Graffer al Grostè and from there take Sentiero Claudio Costanzi (336). Both meet shortly before the ascent to the Bocchetta dei Tre Sassi.
- Val Gelada di Campiiglio
From Passo Campo Carlo Magno head for the bocchetta on foot. First the trail circles around a golf course but later climbs rather steeply through Val Gelada di Campiiglio towards the bocchetta.
The ferrata Claudio Costanzi climbs to the cut between Cima Flavona and Sasso Alto. First you have quite nice but unsecured climbing pitches. Later, at the western base of Cima Flavona several gullys have to be climbed. Once north of Cima Flavona you are awarded great views down Val Gelada di Tuenno on the eastern side of the ridge.
Now the ascent gets very steep at several places and the cable security (or ladders) is missing so that the ferrata get s to be rather difficult. The higher you get the more exposed the ledges become. Some 150m below the summit is a platform, on which we had to turn around due to a knee injury I encountered. The remaining ascent is supposed to be a scramble with pitches of climbing (I+).
I would recommend a ferrata set: harness, short ropes and biners. Much of the trail is not secured by cables so you really need experience. Bring your own food and don't forget the water. And because of rockfall you better bring a helmet as well.