The Koobi Fora site was gazetted as a national monument in 1972 as the Sibiloi National Park. Koobi Fora refers primarily to the region around Koobi Fora ridge – an outcrop of mainly Pliocene/Pleistocene sediments. It is composed of claystones, siltstones, and sandstones that preserve the numerous fossils of terrestrial mammals, including early hominin species. Koobi Fora lies on the eastern shore of Lake Turkana where a unique wealth of prehistoric remains has been found in an area approximately 90km by 30km extending from Ileret in the north to just south of Allia bay.
In the language of the Gabbra people who live near near the site, the term ‘Koobi Fora’ means a place of commiphora and the source of myrrh, which is the common plant in this hot and arid area.
The site is one of the leading prehistoric sites for the study of the evolution of man, and in recognition it was inscribed on the UNESCO World Heritage List on December 7, 1997. This fossil landscape was first discovered by world renowned palaeontologist, the late Dr. Louis Leakey, from the air when he saw the sediments spanning across the area. Koobi Fora was first explored in 1968 by a team from National Museums of Kenya led by Dr Richard Leakey. He established the Koobi Fora Base Camp on a large sandpit projecting into the lake near the ridge, which he called the Koobi Fora Spit.
Koobi Fora has yielded plants and animal fossils spanning to over 7 million years ago with hominid fossils from the Plio/Pleistocene period have been found here. This site comprises approximately 700mi² of fluvial and lacustine sediments representing a broadly continuous sequence of deposition from the Pliocene (5.0 million) to the Early Pleistocene (1.0 million) years old.
Prior to 1960, most of the evidence for the evolution of man during the early Pleistocene was confined to Southern Africa. However, since the earliest excavations at Koobi Fora the greatest body of evidence for early hominid development has been obtained from this site in northern Kenya.