The reserve protects an area in the transition between the Cerrado and Amazon biomes, supporting highly diverse flora and fauna including many endemic species.
The Nascentes da Serra do Cachimbo Biological Reserve has an area of 342,192 hectares (845,570 acres).
In the northern part there are escarpments along the transition to the peripheral depression of southern Pará, where the rivers descend in rapids and waterfalls such as the Salto do Curuá.
Reptiles include typical Amazon species such as the gecko Gonatodes eladioi, the lizards Bachia flavescens and Anolis punctatus, false coral snake (Anilius scytale), pit viper Bothriopsis taeniata, emerald tree boa (Corallus caninus) and Xenoxybelis argenteus.
There are 22 regionally endemic species including red-throated piping guan (Pipile cujubi), snow-capped manakin (Lepidothrix nattereri) and masked tanager (Tangara nigrocincta).
[1] The reserve is classed as IUCN protected area category Ia (strict nature reserve), with the objective of fully preserving the biota and other natural attributes without direct human interference or environmental changes except where needed to restore and preserve the ecology.
The fully protected areas, which cover 6,670,422 hectares (16,482,970 acres), are the Amazônia, Jamanxim, Rio Novo and Serra do Pardo national parks, the Nascentes da Serra do Cachimbo Biological Reserve and the Terra do Meio Ecological Station.
[4] At the time of its creation the reserve had already been occupied for 15 years in about 94 locations by squatters who had moved north from Mato Grosso.
[5] Large amounts of mahogany have been removed from the forests of the reserve via a 923 kilometres (574 mi) network of roads, creating a fragmented and vulnerable landscape.
[3] In August 2015 it was reported that Senator Flexa Ribeiro of the Brazilian Social Democracy Party (PSDB) proposed to split the reserve into a 162,000 hectares (400,000 acres) National Park open to tourists and a 178,000 hectares (440,000 acres) Environmental Protection Area (APA) in which the inhabitants could engage in livestock breeding and commercial production of rice, bananas, pineapples and coffee.