During the summer months it has little water; the ideal flow is found in April/May/early June or after storms.

During the summer months it has little water; the ideal flow is found in April/May/early June or after storms.

From S.P. della Valsesia, upon reaching Balmuccia, continue toward Alagna. After 500 m, there is a small descending road on the left—take it and park immediately at the first hairpin.

Descend and cross the Sesia on the bridge toward Otra di Balmuccia, then reach the village. After the last house, there is a trail ascending toward the small stream, which is almost always dry. After 5 minutes, you reach the last waterfall of Croso del Riale. Climb via traces on the right-hand slope until you find an old unmarked trail leading to "Pra di Prello," ascend for 15 minutes. On the left, you can see the chasm of the gorge; you exit the forest for a stretch (meadow) before re-entering. Continue ascending until reaching a wider, slightly less steep forest, then cut to the left. On the edge of the gorge, there is a group of trees with a boulder nearby: this is the only point where you can descend inside the gorge for 10 meters without a rope. Then there is another group of trees from which you rappel 15 m to enter the stream. Total approach: 25 min.

First C7 right from a tree Then MC right from a small tree (only with high flow, for safety) and C12 right Then MC4 right + C16 right, C10 left (single anchor) Interesting passage with the characteristic “suspended boulder”; C15 right + C25 left (anchor behind the boulder) Then MC8 left + C22 left, C7 right Reach the last 45 m waterfall, doable in a single rappel or divided into C30 right + C15 right (single anchor). After this, exit on the left to rejoin the approach trail; 5 min back to the car. Total: 10 rappels, 2 h. The only exit route is on the right before the last large waterfall; it is clearly marked with rungs and pipes from a water intake. For the rest of the descent, it is impossible to exit or take shelter from possible floods.