 The combination of flat land, heavy rainfall and high tides causes the mangroves to extend up to inland, where they are interspersed with other rainforest species.The ecoregion covers and area of on the Atlantic coast of Maranhão state.The ecoregion is part of the Guianan-Amazon Mangroves global ecoregion, which also contains the Guianan mangroves, Amapá mangroves and Pará mangroves ecoregions.