Half-way through the nineteenth century, after several failed attempts to conquer the desert, the Argentinian government invited the European peoples to populate Patagonia. Thus, in 1865, a vessel named "Mimosa" landed on the shores of Puerto Madryn. It brought a group of Welsh immigrants who would occupy the area and put into practice their varied trades.
These immigrants established an excellent relation with the native Tehuelches as a result of bartering and the exchange of knowledge, abilities and trades. The Tehuelches used to be skilled hunters and the Welsh could build ovens to make bread and butter. Therefore, both parts benefited from this interaction.
After some attempts to set up flour mills, which failed due to their size or capacity, a promising mill was settled in 1896. However, the area where it was built became the object of a territorial dispute with Chile. Eventually, the so-called Comisión de Límites (Boundary Committee) gathered in 1902 under the arbitration of an Englishman: Sir Thomas Holdicsh. He asked all attendants under what nationality they preferred to live and the Welsh chose Argentinian. After such agreement, Argentina obtained 360,000 hectares.
In 1918, a corporation bought a large mill that fostered the stockpile, processing and commercialization of the entire cereal production in the area. This way, Trevelin developed around this mill, gaining its own strength as a population.
Shortly afterwards, the first neighborhood development committee was created and so the town was founded on the left margin of the Percey River. It was the beginning of Trevelin, a Welsh name formed by “Tre” -which stands for “town”- and “Velin” -which means “mill”. And the name Colonia 16 de Octubre, which had been used so far, was dropped.
The decline of the mill activities came under Perón's administration in 1949, when Chubut was declared non-wheat area and the local denizens were forced to find other activities to develop, such as cattle-raising. Today, the venue where the mill used to work has been turned into a museum open to visitors.