The Colorado River is a river in the Southwestern United States and northwestern Mexico, approximately 2,330 kilometers (1,450 mi) long. Here, it can be seen at its mouth, empyting tan sediments into the Gulf of California between the Baja California peninsula and mainland Mexico.
Visible extending across much of the northern border of the Gulf of California, is the Gran Desierto de Altar. One of the major portions of the Sonoran Desert of Mexico, including the only active erg dune region in North America, it reaches more than 100 kilometers east to west, and over 50 km north to south.
The dark brown area amidst the desert sands is the Pinacate Peaks (Sierra Pinacate), a group of volcanic peaks and cinder cones located mostly in the Mexican state of Sonora along the international border adjacent to the U.S. state of Arizona, surrounded by the vast sand dune field of the Gran Desierto de Altar, at the desert’s southeast.