Run by the non-governmental organization Environmental Foundation for Africa, Tiwai is 12 square kilometers in area and located on the Moa River in the Southern Province.

Tiwai belong to the Barri people until the late 19th century when Queen Nyarroh the Barri Chief gave half the Island to the Koya Chief whose territory was on the opposite side of the River Moa River where the Island is located.

[2] Subsequently, some researchers along with the Barri and Koya people then requested that it became a wildlife sanctuary and in 1987 it was official designated a game reserve.

Then, in 1991 civil war broke out in Sierra Leone financial support for the Tiwai was stopped and researchers and tourists were unable to reach the Island.

[4] After the end of the civil war the Environmental Foundation for Africa, a local Sierra Leonean NGO, rebuilt both tourism and researcher facilities on the island.