In 1955, Drucker led a new excavation, funded again by the National Geographic Society, concentrating on Complex A and finally reaching the subsoil at the site, established stratigraphy to discover the constructional history. They discovered more jade artifacts, which were interpreted as ritual offerings, as well as pottery shards. The findings were published by Drucker, Robert Heizer and Robert Squier, (who were also assisted by Eduardo Contreras and Pierre Agrinier) in 1959. At this point most of the site was still unexcavated and in a strongly worded passage Heizer reported that the site was inadequately protected by the Mexican government and a wave of illegal excavations followed the departure of the archaeologists, as well as damage by urban sprawl, the national oil company, Pemex, and the removal of large monuments to museums (without leaving markers as to their original positions).