LIFE ZONES.
There is a great variety of herbs, shrubs, and trees within the monument, as a result of the varied terrain and the range of elevation from the bank of the Rio Grande up to the summit of the San Miguel Mountains on the west boundary. Three life zones, or climatic zones, are encountered in traveling the central part of the monument; the Upper Sonoran zone of pinyon and juniper by the river, the Transition Zone of ponderosa pines on the higher mesas, and, highest of all, the Canadian Zone of spruce, fir, and aspen near Boundary Peak. Each of these zones has its characteristic mammals and birds, so that the population of wildlife is likewise varied and extensive.
Group of cave rooms between Long House and Ceremonial Cave.