The Yuma Desert is a lower-elevation section of the Sonoran Desert in the southwestern United States and the northwest of Mexico. It lies in the Salton basin. The desert contains areas of sparse vegetation and has notable areas of sand dunes. With an average annual rainfall of less than 8 inches (200 mm), it is among the harshest deserts in North America. Human presence is sparse throughout; the largest city is Yuma, Arizona, on the Colorado River and the border of California.