Analysis of 519 obsidian artifacts (pebbles, debitage, cores and small bifaces) by nondestructive X-ray fluorescence from forests and steppes of southern Lanin National Park in the northern Patagonian Andean region, from Lacar (chemical group QU/AP), Lolog (CP-LL 1), Filo Hua-Hum (FHH), Paillakura (Pk, former unknown 1 group), Meliquina (MQ, former unknown group 2) and Yuco (YC) sources. Neutron activation analysis was applied to 29 of the artifacts. We identified for the first time the presence of obsidian from distant Covunco (PC1) in the center of Neuquen. This paper is the first English language publication of our ongoing, ten-year-long research. In accordance with previous work, but using other analytical techniques, the most frequently used sources during the late Holocene remain CP/LL 1 and Pk, here we add YC, mainly by the incorporation of new sites recently surveyed in the islands and the coast of Lake Lacar, next to its source. Another result consistent with previous work is the absence of obsidian from Mendoza and Chilean sources; therefore, we suggest these obsidians circulate just to the east and northeast, allowing us to discuss issues of human territoriality during the Late Holocene.