The Marismas Nacionales–San Blas mangroves occupy an area of 2,000 square kilometers (770 sq mi) in coastal Nayarit and Sinaloa states.

The Marismas Nacionales is an interconnected complex of lagoons and wetlands on the alluvial plain formed by the Acaponeta, San Pedro Mezquital, and Grande de Santiago rivers.

Trees that grow in association with the mangroves include ciruelillo (Phyllanthus elsiae), zapotón (Pachira aquatica), and anona (Annona glabra).

The Marismas Nacionales Biosphere Reserve also support an important number of mammal species, like deer, jaguar, ocelot and lynx.

The direct and indirect impacts of this development, including the city that will be created nearby to house the workers servicing the tourism lodging and attractions, pose a substantial threat to the conservation of the Marismas Nacionales-San Blas Mangroves.