The Sonoran Desert occurs primarily in Mexico. More than two-thirds of its total area is in Baja California and the state of Sonora. In the United States, most of the Sonoran Desert can be found in the southern third of Arizona, with small areas in southeastern California. It is a subtropical desert and the most complex desert in North America. It has great diversity in geological structures as well as the number and variety of plants and animals.
One reason for the many plants and animals in the Sonoran Desert is that it receives rainfall bi-seasonally. Rain falls in this desert during the winter months and also in July and August. Because the rain occurs twice a year, the plants don't have to wait so long between drinks. - NPS
Sonoran Desert is a physiographic province of the North American continent. - AsNotedIn