The trailhead is close to the Vidor campground in Val di San Nicolò. The valley can be reached from Val di Fassa by turning east at Pozza di Fassa. Right after the campground you can find some parking space where you should start the climb.
Looking out of Vallaccia towards Larsec and the Sas Lonch Group
- Start altitude: 1415m
- Summit altitude: 2550m
- Prevailing exposition: north
- Type: 3h on trails, trailless near the summit
- Protection: some cables below Bivacco Zeni, otherwise unprotected
Effort: 1200m gain in elevation
Power: 3 - very strenuous
Psyche: 2 - No exposure but the scree couloir is definitely not for the faint of heart
I would not recommend this route to anyone who is not used to unprotected scrambling on steep scree. The ascent to Forcella Vallaccia is as steep as scree can get, meaning that you need to stay in motion because otherwise you'll slide back slowly again. None of the guidebooks I have describe this route (they all stop at Bivacco Zeni) and to me it is obvious why. This is not for regular hikers!
The start of the climb is harmless enough. You need to follow the road into Val di San Nicolo for about 1 km until it switches to the other (southern) side of Rio San Nicolò. 200m past the bridge a marked trail leaves the road and heads straight up through the forest. After about 10 min the trail splits in two. The left trail will lead you to Baita and Malga Monzoni (outside approach) while the right one leads you to Bivacco Zeni and the inside of Vallaccia.
At first trees obscure the view, you get some nice views northward towards Larsec but the destination is still hidden. After 45 min from the trailhead you cross the tiny Vallaccia Creek and there you get a first glimpse of the towers at the centre of the group. The trail gets steeper and heads directly northward. After some more 30 min you reach a slab which is protected by (unneccessary) cables which leads you almost directly to Bivacco Zeni.
The Bivacco is located on a balcony above the Vallaccia Valley. Some steps southward and you are directly in the centre of the Vallaccia Cirque. Awesome is the only description I can use for that impression. Unfortunately the further route is clearly visible from the Bivacco too. To the left of Punta della Vallaccia's north-western pillar there is a steep chute which leads directly to Forcella Vallaccia. The chute is full of scree and though I haven't measured it I would estimate the slope to be about 45°.
Though not dangerous or difficult a climb of that couloir is as strenuous as it can get. Touch the scree anywhere and it will start to slide downwards. In many spots you just need to keep in motion, a treadmill which doesn't lead you upwards but which keeps you from slowly sliding down. Never have I sweated and panted as much as in this couloir!
But all things have an end and on top you are rewarded with great views. For the Punta della Vallaccia summit you need to turn right (west) to Forcella Costella, for Sas da le Undesc keep to the left. You cross a slope and then climb through steep meadows. The higher you get the less trail you have but the summit is marked by a weird structure (antenna?) so it is hard to miss. Enjoy the great views - you have deserved it!
Hiking gear. Maybe some of the gullies to the left (east) of the main couloir offer better access to Forcella Vallaccia. If you want to check these out you better bring full climbing gear. Rope and helmet should be mandatory!