Leis is the highest settlement occupied all year round in the community of Vals. The people of Vals originally spoke Romansh. In the late Middle Ages German speaking Walsers settled in this area and cleared the trees from the mountainside terraces sometime around 1300, having presumably found their way here via the Misox. In Mesocco, a small municipality in the Misox, there is a neighborhood called Leis.
A Rhætian register of debtors from 1325 tells us that there used to be two mayors in Vals: one Johannes de Valle and one Wilhelm Lampert de Leisa. At that time part of the population still spoke Rhaeto-Romanic and they mostly lived, like mayor Johannes, down in the valley near the church in the square. The Leis Chapel, built in the early seventeenth century, is dedicated to Saint James the Greater, patron saint of travelers and walkers.
Today Leis has around 20 inhabitants. There is a restaurant, and two families tend the mountain meadows. There is year-round access to Leis by road.