Back when Arizona was designated a U.S. territory, scientists had already been exploring its vast landscapes which start from nearly sea level and climb to over 12,000 feet. They were paying particular attention to Arizona’s diverse vegetation and climate.
In 1889, biologist C. Hart Merriam traversed northern Arizona and found six of the seven world life zones he would later describe by latitude and elevation. The existence of such varied life zones across a short distance, and often with just a few hundred feet of elevation change, fascinated scientists. One particular life zone, the extensive stands of ponderosa pine growing at higher elevations from west of Flagstaff, AZ, eastward into New Mexico was particularly interesting to scientists and foresters.