Pinus ponderosa Dougl. and Pseudotsuga menziesii (Mirb.) Dougl. are two species used in afforestation in the province of Neuquén (R. Argentina). They are distributed in very different site conditions, from wet forest to ecotones. They have different growth curves and yields, which are associated with different soil conditions. To compare their growth in different site conditions, as a first characterization, we developed height-age curves from stem analysis obtained from the dominant trees, using Site Index at 14 and 21 years. The best sites contain soils classified as Thaptic Hapludands; Thaptic Udivitrands; deep, Humic Vitrixerands; and deep, Vitrandic Argixerolls.