The purpose of this bulletin is to enable persons not technically trained in botany to identify the coniferous species of the northern Rocky Mountain region lying within the United States. Forest trees of all kinds have interest for all people. Familiar and affection knowledge of them has culture value of a very fine kind. For the people of some sections of the country, a scientific study of the trees of the forest has much practical and commercial value as well. this is particularly true of the forested region of the Rocky Mountains. There is great need for such a guide for teachers and students in this subject, as it will add much to the richness of the school work. This bulletin is divided into three chapters: (1) The forests; (2) The species; and (3) Directions for the study of the conifers. (Contains 37 figures, 1 note, and 2 footnotes.) [Best copy available has been provided.]