The Usumacinta mangroves ecoregion (WWF ID: NT1437) covers the mangrove forests ont the Gulf Coast of Mexico, around the margins of the Laguna de Términos ("Lagoon of Ends").

This region, which is due south of the mouth of the Mississippi River across the Gulf of Mexico, receives an estimated one-third of the wintering birds migrating on the Mississippi Flyway.

They also cover the margins of the lagoon and inland for 5 km or so where the balance of saline and fresh water supports mangrove species.

This climate is characterized by relatively even temperatures throughout the year, and a pronounced dry season.

Periodic flooding prevents the extensive growth of herbaceous species.