There are approximately twelve thousand acres of wild, rugged terrain within which the rock formations and a great ecological diversity are protected. In 1976, Congress decided to further preserve the land, designating 87% of the monument as Wilderness. This precludes any development and human intervention, thus ensuring the preservation of the geological formations for future generations and the continuation of undisturbed space and habitat for the many unique plants and animals that are found in this special region. As well as the exceptional geological aspects of this park, the monument hosts a biological crossroads, a meeting-place of four different ecological regions. In the Chiricahua Mountains, the Sonoran and Chihuahuan deserts, and the Rocky Mountain and Sierra Madre ranges all meet. The convergence of these four biomes makes this area unusually rich in both floral and faunal biodiversity. Rocky Mountain representatives such as the Ponderosa pine and Engelmann spruce co-exist beside the Soap tree yucca from the Chihuahuan desert. Stately Arizona sycamore and various types of oak dot the well-watered canyons. Apache pine grows here at the most northern end of the Sierra Madre range. Chihuahua pine is found, as are Douglas and White fir, Arizona cypress, Cane cholla, Prickly pear and several species of ferns, mushrooms, and fungi. There are five major drainages within the monument, several with intermittent creeks that support a mixture of deciduous and evergreen woodlands. The heavily forested canyons provide habitat for numerous wildlife, including coatimundi, white-tailed deer, javalina, and many species of birds; over three hundred bird species are found in the Chiricahua Mountains, some of whom have migrated north from Mexico.
The Chiricahua Mountains are part of the Madrean Archipelago, a collection of forty neighboring mountain groups that lie between the Colorado Plateau and the Sierra Madre Occidental. It is so named because it resembles an oceanic archipelago - a sea dotted with islands - only here the sea is hot desert grassland. We call these isolated mountain ranges ‘sky islands’. The Chiricahuas are a perfect example of a sky island that formed during the Basin and Range faulting.