The starting point of this highly satisfactory excursion is the dirt road on the left just after S. Giacomo rest stop, at the entrance to the wild Val Pettini. Following the indications to Trela lodges, reach the suggestive encounter point of four verdant valleys, where delicious mountain cheeses are produced. The trail on the left leads to Bocche di Trela (2348 m a.s.l.), offering a vast panorama that reaches Valfurva. After descending towards Case Vezzola, a junction invites to go on the right and climb up val Vezzola. After walking two kilometres along the trail no. 176, a plateau leads to bocchetta Trelina and, at the end of the descent, to Trela lodges. The most fatigued ones can conclude their excursion here by taking the same road; whoever is willing to continue the walk can go on the left and climb up val Trela until finding, on the right, a trail leading to bocchetta di valle Lunga (2335 m a.s.l.). Here, the descent through the small valley bearing the same name intercepts the road of val Pettini, walked at the beginning of the excursion.