This work assesses ecological and cultural indicators, based on information published and from the field research itself as part of the project ‘From ethnic to pre-history in Argentina’s Grand Chaco’, the ultimate purpose of which is to reconstruct regional biocultural history. In a geographically broad area, with an ethnographic body of information much broader than archaeological data, the data provided by the survey of native societies and its handling, in a complementary manner, together with archaeological evidence, facilitate the validation of models and explanatory hypotheses. As well as contributing to the achievement of the objectives of the project, ethnographic information enables verifiable inferences to be made in the archaeological and environmental register. In the prehispanic past, the use and organisation of space by human groups in Southern Chaco has distinctive nuances due to its ecological and cultural characteristics. The subsistence economy that has prevailed from the very early stages involves harvesting, hunting, fishing and complementary cultivation. On the basis of indigenous Spanish-speaking contact, aspects of the above model remain in force, with cultural adaptations being made to environments in critical situations, and in some cases completely denatured. Such an environmental dynamic would appear to have led to the search for adaptive regenerative strategies of a harmonious balance between man and his entome in the hunters of Chaco. Although, at present and apparently, some of these groups do not fit into this caze/harvest paradigm, in their way of life a reminiscent of the ancestral method, which, as Barnard ‘, is a form of thought, emerges into their way of life.