C. Hart Merriam's investigations into distinct life zones that follow the slopes of the San Francisco Peaks in northern Arizona have helped shape present research into 6 dominant vegetation types along a 2200 m elevation gradient running from near the top of Mt. Humphreys to the Great Basin Desert floor of the Colorado Plateau. These life zones correspond to specific elevation ranges, but also correspond to specific latitudinal ranges from Sonora, Mexico to the Arctic Coast of Canada. Thus, the existence of these 6 life zones within this relatively small area of northern Arizona is unique. This section will describe these distinct areas in detail for better understanding of our project. You can explore each area by clicking on the image above.