This work presents an overview of the physicochemical and biological studies carried out along Rio Agrio and in different hot springs belonging to the geothermal Copahue volcano system, in Neuquén Argentina. This is an extreme environment characterized by wide ranges of temperature, pH (<1 to 8) and heavy metals concentration. In these extreme conditions chemolitho-autotrophic bacteria, archaea, heterotrophic bacteria, yeasts and filamentous fungi were detected. Members of Leptospirillum ferrooxidans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidianus spp., among others, were successfully cultivated and physiological properties of different isolates were determined. Additionally, bioleaching and biooxidation of regional ores were carried out using mixed native cultures.