Lys (Dora Baltea)

The Lys (Walser German: "Liisu" or "Lyesu") is a small river (classified as a "torrente").
Geography.
It flows from the Lys Glacier on the south side of the Monte Rosa massif, at the foot of Vincent Pyramid, elevation , and runs through the Gressoney Valley, flanked by a road, through the following municipalities:
It converges with the Dora Baltea (fr. "Doire baltée") as a right tributary at Pont-Saint-Martin.
Its left-side tributaries are Avant-Cir, Glassit, Loo, Mos, Niel, Pacoulla, and Tourrison. From the right it receives: Rû de Nantay, Stolen and Valbona.