Here is a world of barren rock and biting cold. At 12,000 feet and above the eternal snows lie deep on the peaks. Yet, even though at first glance there seems to be little evidence of life of any kind, a close scrutiny will reveal low mat-like plants growing among the exposed rocks and tiny paths leading to burrows in the rock slides. Among the larger mammals there are few other than the mountain sheep that can endure the rigors of this inhospitable region. These are the zones of the Southwest uplands. Altitudes given are approximate and apply to such mountain ranges as the San Francisco Peaks of Arizona and the Sangre de Cristo Mountains in New Mexico. As one travels farther north the zones descend ever lower until in the Far North the Arctic-Alpine Life Zone is found at sea level. Since climate more than any other factor, determines the types of plants and animals that can live in a given area it is only natural that on these mountain islands many species entirely foreign to the surrounding deserts are found at home. Though it would seem that because of the relative abundance of water at higher elevations the upland species would have the better environment, this is not entirely true. Balanced against this advantage are the severe winters which, in addition to freezing temperatures, usher in a period of deep snows and famine. Even though many species show a high degree of adaptation to these conditions, an especially long or cold winter season will result in the death of weaker individuals. _Man and Wilderness_ The effects of man’s presence on the upland species is perhaps not as serious as on those of the desert. Though he has been instrumental in upsetting the balance of nature everywhere, it has been chiefly through agriculture and grazing. Because of the rough broken character of much high country in the Southwest the first is impossible in many cases and the second only partially successful. There are other factors however which menace the future of the upland species. Among these are: hunting pressures, predator control, and lumbering. Even fire control, admirable as it may be for human purposes, disrupts the long cycles which are a normal part of plant and animal succession in forested areas. These are only a few of the means by which man deliberately or unconsciously decimates the animal population. They are set down as a reminder that unless conservation and science cooperate in management problems, it is conceivable that many of our common species could well become extinct within the next 100 years. Our natural resources are our heritage; let us not waste the substance of our trust.