Rocky Mts. type of coniferous forest on a shallow canyon side with rich (mainly deciduous) woody vegetation along a river bank. Coll.: Debreczy, Biró, Rácz et al.; Associating species: Acer glabrum, Mahonia repens var. pumila, Pinus ayacahuite var. brachyptera, Pinus durangensis, Populus tremuloides, Pseudotsuga sp., Quercus candicans, Ribes madrensis etc.; Dendrological Atlas Project Collections # 39711(a); Sheet 2/2