The main aim of this project is to make reliable records of Gastrotheca christiani, a lost frog that is missing since 1996 as the keystone for any future conservation effort on this endangered and unique marsupial frog. As second objective we intend to develop a long-term monitoring program for the endemic and threatened anuran species of Calilegua National Park as Rhinella gallardoi, Rhinella rumbolli and Telmatobius oxycephalus, and to actualize the conservation status and population trends of these species in the most inaccessible region of the national park. We aim to describe the diversity of anuran assemblage inhabiting the uppermost area of Calilegua National Park at the montane grasslands. Confirm the hypothesis of the importance of the Montane grassland as climatic refugia for endangered frogs species and make recommendations to Calilegua NP authorities about management of human activities in the area. To edit an educational book for kids with Gastrotheca christiani's life traits, conservation status, and the relevance of preserving its natural habitat in the Yungas forest of NW Argentina.