We present the results of XRF analysis for 59 obsidian samples from 11 archaeological sites in Auca Mahuida region, Northeastern Neuquén, Argentina. The results indicate that several obsidian sources were utilized; however, the intensities of their exploitation were variable.Strong differences appear between the Colorado river basin, characterised by a low variability of obsidian groups from northern Neuquén, the Auca volcano, with a low variability of obsidian groups but from local sources located north and southwards from the study area; and along Bajo del Añelo, which presents a high variability of obsidian groups from several local and nonlocal sources. The pattern recorded fit different mechanisms of access to the sources and conveyance of obsidian across the landscape. Two distinct paths of direct access are suggested