The Upper Gulf of California is a region in northern Mexico, in the corner formed by the border of the states of Baja California and Sonora. The area is composed of marine waters, swamps, wetlands, and deserts. Its population of around 69,700 inhabitants is distributed in 210 locations. The three most important urban settlements are San Felipe, El Golfo de Santa Clara, and Puerto Peñasco. The Cucapas are a representative indigenous ethnic group in the region. The main economic activity in the area is fishing, and catch volumes can reach an estimated 72.4 million pesos, one of the highest nationwide. The Upper Gulf hosts the Biosphere Reserve of the Upper Gulf and Colorado River Delta, covering 9,347.56 km2 in marine and terrestrial environments. It is a place of great environmental importance due to the abundance of wildlife in the sea and the delta. Notable among the wildlife is the vaquita marina, the only marine mammal exclusive to Mexico, and the totoaba, a fish of great commercial importance. Both are endemic species to the Gulf of California and are in serious danger of extinction. The Upper Gulf is also home to species with high commercial value, such as shrimp, crabs and gulf corvina.