The Reserve is located on the North Coast of Nayarit and has an area of 133,854 ha that includes a large network of brackish coastal lagoons, mangrove forests, swamps, deltas, and marshes. This area represents between 15% and 20% of the total mangroves that exist in the country.The Reserve is located on the North Coast of Nayarit and has an area of 133,854 ha that includes a large network of brackish coastal lagoons, mangrove forests, swamps, deltas, and marshes. This area represents between 15% and 20% of the total mangroves that exist in the country.

The reserve protects typical ecosystems of the Nayarit coast and covers the municipalities of Acaponeta, Rosamorada, Santiago Ixcuintla, Tecuala and Tuxpan. 

Salty and fresh waters mix forming coastal lagoons that have become the refuge for about 100,000 aquatic birds of 446 different species.

Within the vegetation there is low deciduous forest, palm grove and mangrove including red mangrove, black mangrove, buttonwoo mangrove and white mangrove. 

The reserve is also the home of 98 mammals species, including jaguar, ocelot, tigrillo and lynx, among many others, 20 reptiles and amphibians, including the boa, coral snake, river crocodiles and olive ridley turtles. There are 99 endemic species and 73 endangered species.

In the part that comprises the Már de Cortés (258,593 km2), it is estimated that there are more than 700 fish species. 

One of the most interesting places in the reserve is the Jaguar Island, habitat for amazing jaguars and the ideal place to be in contact with nature.