In the transformation process of medieval economy, the influence of the monasteries and the presence of feudal lords, who started transalpine commerce, favoured the settling of Walser colonies in Alta Valsesia from the second half of the XIII century. The founding of the Walser colonies can be placed around 1285 even if there are no documents to validate this. In the treaty of Brusson in 1270 there is definitely no mention of the existence of Walser settlements on the mountain pastures of Pietre Gemelle. Slowly between the end of the 200's and the beginning 300's, the ancient monastic pastures, in particular those on the lower valley stations, were transformed into stable Walser villages. The oldest testimony dates back to 1302 and relates to the colonist-farmer Pedemonte "Anrigeto Alemanno of Apud Mot" who with a deed constituted the dowry for his daughter, forcing his son-in-law Pietro Gualcio to participate in the management of the pastoral-agricultural business of the family. In 1319 however, the hereditary leasing rights of Giacomo, Anrigeto Ursus' son, regarding the territory Dosso dei Larici, ceased and passed on to the brothers Zanino and Nicolino of Borca, Macugnaga. This is the fact that makes you think that the first colonies stationed in Pedemonte might have arrived from Macugnaga. Other groups of colonies settled on the surrounding grassy terrain  giving life to small self-sufficient villages that can be dated back to the first half of the 300's: Goreto is mentioned in documents from 1350, Piane in 1354, Rusa in 1389, Merletti in 1413, Oro and Ekku in 1414. Bonda in 1417 and Montella in 1438.