Identify Major Rocky Mountain Trees Using Forest Zones

The Intermountains and Rocky Mountain forests of the North American west have evolved into a fascinating system of natural order. This order makes identifying common trees easier.
I have included the most common trees you will find growing at an elevation of over 4,500 feet and up to the treeline. Different tree species generally thrive only at specific elevations called zones or belts. The lowest reaches of the intermountain region are much dryer than the higher reaches and include trees adapted to dry conditions. Vegetation at higher reaches depend on available moisture in the form of both rain and snow.

The major regions between desert and treeline are:

- The Pinyon-Juniper Belt
- The Pine-Oak Belt
- The Fir-Aspen Belt
- The Fir-Spruce Belt

Forest Biomes of North America