In 1881, when already 90% of the chacras of the river Chubut inferior was granted to the Welsh colonists, the pressure began to explore toward the mountain range in search of new lands. Adding this the national government's restlessness with regard to the definitive layout of the frontier with Chile, it was organized in 1885 an expedition of Welsh colonists to the control of the governor of the territory L. J. Fontana that discovers the fertile valleys of the river Percey, Corinth and Esquel in the same year. Welsh called it Cwn Hyfryd, "Valle Hermoso", but it passed to the history like Valley 16 de Octubre (it dates in that the Law of National Territories was signed, October 16 1884).
In the two following years, the Welsh, with the governor's support, request the lands for their colonization. In 1888, a second expedition began with the colonization of the valley, agricultural-pastoral colony October 16, with a surface of 125.000 have, distributed among 50 families with a squared league each a (2.500 have). The colony extended from Esquel until The Humped one in the south. In 1895 there were 298 residents of which 166 were Welsh.
The mensurations began in 1888, but the definition of the limits with Chile it deferred the delivery of the holding one and newly in 1906 the fields were wired. Toward ends of the century won ovino arrived and I vaccinate to populate the valley, wheat was sowed and the first floury mill worked.
Due to the character of the colony agricultural-cattleman, the population was dispersed in the whole extension of the valley. Esquel, located in the north end of the Welsh and adjacent colony with the big properties of the English Company of Lands of the South, became with the time the most important populational and commercial center in the colony.
From ends of last century, Percey existed on the river a chapel and a school, separated by 8 km. Considering the isolation and the distances among the residents, the chapel charged importance for Sunday meetings. Next to her it settled a mill, and soon conformed to a baptized urban nucleus Trevelín, "town of the mill". During the first decades the development of the town was linked with the agriculture and with the mill.
In 1927 you creó the first Commission of Development. Esquel was developed like commercial and administrative center and Trevelín became the cultural center and religious of the Welsh community. Here the Eisteddfod takes place, musical, poetic and literary competitions, of old Welsh tradition. Today is an important commercial center and it possesses several living rooms of tea, restaurants and a museum. The cattle raising and in smaller scale the agriculture is still the pillars of the economy of the valley. The original lots suffered subdivisions for inheritance and today 15% of the inhabitants it is only of Welsh origin.