Rivers that flow into the Gulf of California include the Colorado, Fuerte, Mayo, Sinaloa, Sonora, and the Yaqui.

Maximum depths exceed 3,000 meters (9,800 ft) because of the complex geology, linked to plate tectonics.

[citation needed] One recognized transition zone is termed the Southwestern Baja California peninsula.

[15]) Geologic evidence is widely interpreted by geologists as indicating the gulf came into being around 5.3 million years ago as tectonic forces rifted the Baja California peninsula off the North American Plate.

[17] Furthermore, hydrothermal vents due to extension tectonic regime, related to the opening of the gulf, are found in the Bahía de Concepción, Baja California Sur.

In fact, many of the islands of the gulf are the result of volcanic eruptions that occurred during the early history of Baja California.

Because of the vast expanse covered by this federal protected area, conservation and management is carried out through a system of four regional directorates (one per state bordering the Gulf of California).

Porous rocks will naturally have more cracks and crevices in them, making them ideal living spaces for many animals.

However, the data vary wildly according to the species being studied, and the gulf's ability to recuperate after years of overfishing remains uncertain.

Moreover, changes in terrestrial ecology, such as the vast reduction in flow from the Colorado River into the gulf, have negatively affected fisheries, particularly in the northern region.

Its more than 900 islands are important nesting sites for thousands of seabirds, and its waters are primary breeding, feeding, and nursing grounds for myriad migratory and resident fish species.

Water pollution is a problem in the gulf, but the more immediate concerns are overfishing and bottom trawling, which destroys eelgrass beds and shellfish.

The thousands of miles of coastline are remote and difficult to police, and the politically powerful commercial fishing industry has been slow to embrace even economically viable conservation measures.

At present, the Mexican government and business interests have promoted a macro-level, tourist development vision for the gulf, the impacts of which on local ecology and society are uncertain.

In 2019, the gulf was added to the List of World Heritage in Danger because of concerns of the imminent extinction of the vaquita, an endemic porpoise in the area.

The well-developed shrimp and sardine fleets of Mazatlán, on the Mexican mainland's Pacific coast, heavily exploit the commercial fisheries of the southern gulf.

[3] Locals have alleged the existence of a giant creature known as the "Black Demon" (Spanish: El Demonio Negro) of the Sea of Cortez.

It is usually considered to be a black shark, and less commonly as a whale, measuring about 20 to 60 ft (6.1 to 18.3 m) and weighing 50,000 to 100,000 lb (23 to 45 t),[25][26] similar to the estimated length of the megalodon.