This website is dedicated to the natural history, educational, and research activities being conducted throughout the life zones that occur along the elevation gradient of the San Francisco Peaks. The Life Zones concept was proposed by C. Hart Merriam as a result of his survey of the San Francisco Peaks. Life Zones are predictable vegetation types that occur along elevation and latitudinal gradients. The San Francisco Peaks region contains life zones that range from true desert to above the tree line.