The Pic de Fon forest at the southern end of the range is a relatively intact area of approximately 25,600 ha that contains many typical flora and fauna of the Guinean montane forests ecosystem, including endangered species such as the Nimba otter shrew (Micropotamogale lamottei), the West African chimpanzee (Pan troglodytes verus), the Diana monkey (Cercopithecus diana diana) and the Sierra Leone prinia (Schistolais leontica), a bird of the West African highlands known from only three other sites in the world.

[8] The area has so far been protected by relative isolation but its biodiversity is now threatened by the encroachment of agriculture, unregulated bushmeat hunting, logging, uncontrolled bush fires, road development, destructive mining operations by foreign companies and human population growth.

Land tenure conflicts and ecologically destructive subsistence farming practices (slash and burn agriculture), exacerbated by poverty, also pose problems for the environment.

[9] Simandou has the potential to become the site of the largest integrated iron-ore mine and infrastructure project ever developed in Africa, consisting of a large new source of iron ore and creating a 650 km new railway to the Guinean coast at Matakong.

[11] However, a version of the full original mining project was re-instated in late 2019[12] and confirmed in 2020 with the signing of a new agreement[13] with the Chinese company SMB-Winning.