Las Lajas is located on the right shore of Agrio River at the Andean foothills, where National Routes 22 and 40. The Pino Hachado Pass, which joins Argentina and Chile, is west of the town. Las Lajas is from Zapala, from Neuquén City and from Buenos Aires. It has an elevation above mean sea level (AMSL). The local poorly developed soils are composed of a low percentage in organic matter. They belong to the entisol and aridisol orders of the USDA soil taxonomy. Besides the Agrio River, waterways in the area include the Las Lajitas and Liu Cullín Creeks.