"The archaeological studies in the Mirador Basin have focused on understanding the origin, development and collapse of the Preclassic Maya civilization, together with the conservation and preservation of the archaeological sites and their natural surroundings. This presentation will introduce the studies of the 2004 season that increased our knowledge of these natural and cultural processes. The mapping of the site’s central section continued using a total station. This offered a site perspective never seen before. Also, part of the archaeological work consisted of testing sites in the West Group in which there is data showing some evidence for the site’s collapse happening at the end of the Late Classic period. Furthermore, excavation pits at the main steps of Structure 34 show the singular importance of this building in the past and indicates the importance of implementing new means of conserving and consolidating Preclassic buildings. Excavations carried out at La Muerta, El Mirador, include final work on Structures A1 and A2 where important information was obtained relating to the building’s architecture. Structure A2 was confirmed as being Early Classic with a network of passages allowing access to the innerfunerary rooms for subsequent generations. Furthermore, the existence of a third level to the building was proved, smaller in dimension but with the same system of passages. Structure A1, beside A2, revealed important information about its function such as the existence of heads modeled in stucco in the upper room of the building. The presence of these heads suggests a representation of faces of Preclassic ancestors, implying a ritual function relating the location of these two structures in La Muerta.The 2004 field season also produced final results in the consolidation and restoration accomplished in El Mirador, rescuing Preclassic and Classic buildings that were in imminent danger of collapse. The final process of architectural consolidation work at El Mirador implemented a vanguard methodology for the conservation of the buildings as well as the stucco artwork which allows at the same time the showing of Preclassic Maya architecture for educational and tourism purposes. This methodology proposes unique measures to date, using the same Prehispanic techniques and material, following a rigorous program of execution and monitoring.The preliminary results have shown very satisfactory evidence." (source éditeur)