The town of Río Mayo was created on August 22, 1935 and it was not until 1941 that the Government of Chubut created the first Neighbors’ Association to officially administer the new settlement.
Its background dates back to 1885, when an expedition led by the governor of the territory of Chubut, Lieutenant Colonel Jorge Fontana, explored and discovered the river the Tehuelche people used to call A'Ayones (“marshland”).
Don Gregorio Mayo belonged to the group called “Los rifleros del Chubut” (Chubut’s Riflemen) and, as an assistant to the governor, he performed a very important task during this mission.
During this surveillance raid, like in previous ones, they searched for areas suitable for agriculture. The “riflemen” made reports for sheep husbandry in the area and they specially followed the Senguer River course from the lake bearing the same name up its mouth in Lake Muster.
The same expedition recognized and chose the settlement then known as Colonia 16 de Octubre, now called Trevelin. Later on, they toured and named the area of Lake Fontana, where the Senguer River starts.
“From the campsite to the hills, we traveled for a league and a half heading East-Southeast. We trekked cross country to avoid the peaks. The whole area of the valley is poor and the quality of the countryside does not justify populating it with cattle. To the west, there is a nice valley crossed by a creek we came to call Mayo. We will name the valley Franco." This is an excerpt from their logbook.
Governor Fontana named this place Río Mayo to pay tribute to its explorer. Years later, the hamlet known as “Paso Río Mayo” or else “Bajo Río Mayo” would be established there. This site was considered excellent for carts to cross and to take a rest. Thus, the more willing adventurers settled down in spite of the weather harshness and the loneliness.
In consequence, history was woven from the economic activities developed in the area. Sheep husbandry was one of the pillars that still remain drawing the gaps of this regional culture.
It was not until 2001 that Río Mayo was declared Rural Tourist District. It became the axis of the Central Patagonian Corridor as a result of its natural and economic resources.
Furthermore, ever since 1984, Río Mayo has been the seat for the National Shearing Festival, where the sacrificed tasks of rural men and the significance of this regional economy based on extensive sheep husbandry stand out.