The group's name refers to the birth city of Guerra and López, Treinta y Tres, Uruguay, on the banks of the Olimar Grande River.

In the 1960s, they were part of the first movement of singing popular Uruguayan songs alongside Alfredo Zitarrosa, Daniel Viglietti, José Carbajal, Numa Moraes, among others.

Despite having a great attachment to their country, they were not alien to social, cultural and political movements then taking place across Latin America.

This led them to participate in various international calls, for example, "Encounter with the protest song" convened by La Casa de las Américas of Cuba,[clarification needed] and conducted between 9 July and 10 August 1967.

As social unrest increased in Uruguay during the 1960s and the early 1970s, Los Olimareños, being consistent in their grassroots support, gradually began to include criticism of the repressive government in their songs.