Rocky Mountain Tree Finder a Manual for Identifying Rocky Mountain Trees
Rocky Mountain Tree DistributionClimate limits where trees can grow. The very things people like about the Rocky  Mountain climate--cool summers and deep snow at high altitudes, year-round dry  sunshine in the low altitudes--are hard on trees. The Rockies have abundant water and  warmth, but not in the same places. Trees here must adapt to extreme temperatures, intense sunlight, and drying winds.Each tree's range has an upper limit, the altitude above which it's too cold for the tree to grow, and a lower limit, below which it's too dry.Some trees are adapted to hot, dry foothills: A three-inch ponderosa pine seedling may  have roots two feet long. It can take soil surface temperatures of 180 F (82 C),  but a heavy frost can kill it.Other trees can survive short summers and bitter winters: The new needles of subalpine  fir resist frost, and its branches shed heavy snow. But its roots are shallow and could not  survive the dry heat of the foothills.The next pages describe five LIFE ZONES found at different altitudes in the Rocky  Mountains. Some trees grow in several zones, but if you know what zone you're in you  can usually tell what trees you'll find.--This text refers to an alternatePaperbackedition.