For almost a month, PIRE members Rose Oelkers, Milagros Rodriguez, Laia Andreu-Hayles from LDEO-Columbia (EEUU), Ernesto Tejedor from UAlbany (EEUU) and Eugenia Ferrero from IANIGLA-CONICET (Argentina) toured Bolivia in search of centenary trees, with which to infer past climate variability and thus better understand the functioning of both the general climate circulation system and the South American Summer Monsoon. Some of these specimens are found at more than 14000 feet, so it was a real challenge to collect those samples. In addition, some of these specimens are the trees growing at the highest altitude on the planet, so they are very good indicators to reflect climate changes.