The State of Maranhão has surface areas of the order of 331 thousand km², being the eighth largest state in Brazil and the second in the Northeast in territorial extension. The State has 217 municipalities and two Metropolitan Regions: Greater São Luis and Southwest Maranhense. The Maranhão portion of Amazonia Legal covers an area equivalent to 80% of the territorial area of the State, about 264,000 km². In this area are located 188 municipalities of Maranhão.
The State has five Geographical Meso-regions, subdivided into 21 Geographic Microregions, where its 217 municipalities are insertedThe municipal boundaries were established based on IBGE Resolution No. 05 of October 10, 2002.
Deforestation is concentrated in an area called the 'Deforestation Arc' , passing through Tocantins, part of Pará and Mato Grosso, the entire state of Rondônia, the south of the Amazonas arriving at Acre. According to the Forest Code, the region delimited by the Legal Amazon rules on the use of rural property, as properties within the Legal Amazon are obliged to maintain 80% of the area as
legal reserve in the Amazon Biome and 35% in the Cerrado biome. Those located properties outside the limits of the Legal Amazon need to conserve 20% of the property as reservation.
The territory of Maranhão consists of the biomes Amazônia, Cerrado and Caatinga, which gives it great morphological and environmental diversity.