Construction of the Malpaso Dam in northwestern Chiapas was the impetus behind the joint Instituto Nacional de Antropología e Historia and NWAF salvage project along the Grijalva and upper Negro Rivers in the mid-1960s. One hundred and five sites were recorded and investigated. A final chapter co-authored with John Clark assesses the findings of this project in light of what is known to date about Zoque prehistory in Chiapas. Published by New World Archaeological Foundation.