Coniferous forest occurs in the
higher mountain ranges throughout the Sonoran Desert. This Rocky
Mountain montane forest is the dominant vegetation of the cold- temperate Rocky
Mountains. Its elevation increases southward until it is pushed off the tops of
the mountains by excessive aridity and warmth in Mexico. In the mountains west
of the Sonoran Desert are isolated islands of Sierran (as in Sierra Nevada)
coniferous forest, characterized by different species of conifers and other
plants.
