By far the most noticeable natural features in the monument are the rhyolite rock pinnacles for which the park was created to protect. Rising sometimes hundreds of feet into the air, many of these pinnacles are balancing on a small base. Though incredibly stable, they seem ready to topple over at any time.
An important natural feature found in the park, and integral to the presence of flora and fauna and the magnificant rock spires, is water. The freezing and thawing of water has helped in the creation of the "wonderland of rocks," slowly eroding the rhyolite tuff rock over thousands and thousands of years.
Although water flows only intermittently on the surface, the park contains all or parts of five major watersheds in the the northern Chiricahua Mountains. Seeps and springs are vital to the survival of most faunal species, and the one wetland marsh in the park is host to two sensitive plant species. Groundwater supplies 100% of that needed by both the visitors to the park and the park staff.
The combination of these natural features as related to geology and water, along with other resource necessities, have helped to determine the floral communities of the park. Rich in diversity, the monument boasts many plant communities, including grasslands, deciduous and evergreen forests, scrublands, and deserts. These different communities are the result of changing elevations, as the mountain range rises up like an island from a sea of grass. These plant communities intermix throughout the monument, creating a truly diverse mosaic of species associations.