Omo National Park, the largest in the country, with an area of 4,068 square kilometers, It is a vast expanse of true wilderness, adjacent to the Omo River, which flows southwards into Lake Turkana and is one of the richest and least-visited wildlife sanctuaries in eastern Africa. Eland, Oryx, Burchell's zebra, Lelwel hartebeest, buffalo, giraffe, elephant, waterbuck, kudu, lion, leopard and cheetah roam within the park's boundaries. The Omo Valley is virtually free of human habitation but is rich in paleo-anthro-pological remains. According to scientific research done in 1982 by the University of California at Berkeley, hominid remains from the Omo Valley probably date back more than four million years.
The Omo River, which is 760 km long, originates in the central, south-western highlands of Ethiopia, where it is known as the Gibe. Its final destination is Lake Turkana, close to the Kenyan border. Since 1973, the river has proved a major attraction for white-water rafters. The season for rafting is between September and October, when the river is still high from the June to September rains from high land but the weather is drier around Omo.
The river passes varied scenery, including an open gallery forest of tamarinds and figs, alive with colobus monkeys. Under the canopy along the riverbanks may be seen many colorful birds. Goliath herons, blue-breasted kingfishers, white-cheeked Turaco, emerald-spotted wood doves and red-fronted bee-eaters are all rewarding sights, while monitor lizards may be glimpsed scuttling into the undergrowth. Beyond the forest, hippos graze on the savannah slopes against the mountain walls, and waterbuck, bushbuck and Abyssinian ground hornbills are sometimes to be seen.