The highest mountain areas of this southeast Arizona section contains Madrean Sky Islands of mountain sky islands. Sulphur Springs Valley is one of the largest and driest subsections in this otherwise mountainous region. From north to south at the west of the valley are the Little Dragoon Mountains, the Dragoons, and the Mule Mountains. The south end of Sulphur Springs Valley also has three small ranges associated with the southern Chiricahua Mountains, the Swisshelm, Pedregosa, and Perella Mountains.