[1] It adjoins the 83,381 hectares (206,040 acres) Manicoré State Forest in Amazonas, a sustainable use conservation unit created in 2005.

[8] A series of executive decrees and state laws have defined and redefined the area of the Rio Roosevelt Ecological Station.

The extractive reserve was later occupied by illegal squatters, and was revoked by a judicial order in 2013, confirmed by the state legislature in January 2015.

The judge stated that the lack of environmental protection in the extractive reserve was causing it to be devastated, and it could not be considered compensation for the loss of the "4 Reservas".

Decree 58 of 13 April 2015 redefined the area of the ecological station as about 96,925 hectares (239,510 acres) with a perimeter of 150 kilometres (93 mi) in the municipality of Colniza.

[9] The ecological station is in one of the most pristine areas of Amazon rainforest in Mato Grosso, away from the zone of agricultural expansion, with sparse population and little deforestation.