[5] Gambella was established during 1974–1975 to protect habitat and wildlife, especially the Nile lechwe and white-eared kob, two antelope species thought to have been endangered at the time.

[6][7] Animal populations in the park have declined because of agriculture,[8] cotton farming, hunting, poaching, and the creation of refugee camps, especially following the 1983–1985 famine in Ethiopia and by the displaced Sudanese.

[7][9][10] In 2012, Bantayehu Wasyihun, head of the park's office, said infrastructure development was underway to make Gambella more accommodating to tourists.

[12] Sixty-nine mammal species are found in the protected area, including the African elephant, African buffalo, bushpig, common warthog, Nubian giraffe, hippopotamus, Nile lechwe, tiang, waterbuck, cheetah, leopard, lion, mantled guereza, olive baboon, patas monkey and spotted hyena.

[3][7] Plant species along the Akobo and Baro rivers include the Acacia victoriae, Arundo donax and temba (Pennisetum petiolare).