The Geologic history of the Chiricahua Mountains concerns the Chiricahua Mountains, an inactive volcanic range located in Coronado National Forest of southeastern Arizona, in the United States. They are part of an "archipelago" of mountain ranges known as the sky islands that connect the Sierra Madre Occidental in Mexico with the Rocky Mountains. The Chiricahua Mountains are home to a number of unusual geologic features associated with the , some of which are protected by Chiricahua National Monument. The landscape has been dominantly shaped by faulting due to Basin and Range extension during the Miocene, volcanic activity, and erosion.