It protects the watershed and headwaters of several tributaries of the upper Itapecuru, an important source of water for twenty cities in Maranhão including São Luís.

The families with the greatest number of species were Malpighiaceae, Leguminosae, Rubiaceae, Cyperaceae, Convolvulaceae, Melastomataceae, Malvaceae, Vochysiaceae and Dilleniaceae.

[3] Fauna includes endangered species such as the king vulture (Sarcoramphus papa), giant armadillo (Priodontes maximus) and bush dog (Speothos venaticus).

Other species include Amazon parrots, parakeets, partridges, seriemas, margay (Leopardus wiedii), deer, cobras and armadillos.

[9] The Mirador State Park was created by decree 7.641 of 4 June 1980 on state-owned land to protect the river sources.

Administration is the responsibility of a department of the State Secretariat of Environment and Natural Resources (SEMA), which outsources the work to a cooperative.

[10] On 23 November 2009 it SEMA announced that it would spend R$500,000 to prepare a management plan, starting with a biotic diagnosis lasting from 8 months to a year.

[2] Law 9.316 of 23 December 2010 recognised the Cooperativa dos Técnicos em Proteção Ambientaldo Parque Estadual de Mirador as providing a public service in managing the park.

[9] In January 2016 the State Government announced that it would hold public hearings in Mirador on the condition of the park to address the demand of the vice-prefect of the city, José Ronilde Pereira de Sousa ("Rony") to fight environmental degradation due to fires and poaching.