Las Víboras (the snakes) belongs to the department of Tordillo (tordillo means a grey furred horse).According to the legend, a wild “tordillo” horse that lived in this area and was never able to be caught, gave this original name to the district.

In these planes situated in the south of the river Salado (salty river) used to live indians until in 1740 the Jesuits moved into them. They converted the indians to be able to extend civilization.

Later on, governors and wealthy families discovered that these lands had a great future of exploitation.

That is how, in the year 1814 the first settlers arrived, among the "Anchorena" and the "Rosas" family. Dolores is recognized for being the first unified town of the native lands. In the year 1839 the first treaty of peace was established in the estancia of Las Viboras.

The federalist governor Juan Manuel Ortiz de Rosas lived in the farm during some years and built different houses to hide from his opponents and to be able to train his soldiers for war. An other legend says that a character of the book "Martin Fierro" written by José Hernández used to live there in one of these houses built by Rosas. (Martin Fierro is one of the most important books of the Argentine culture).