Koobi Fora is a region around Koobi Fora Ridge, on the eastern shore of Lake Turkana, Kenya. It is in the territory of the nomadic Gabbra people. The term East Turkana can be used for the whole area.

The ridge is an outcrop of mainly Pliocene/Pleistocene sediments. It is composed of claystones, siltstones, and sandstones that preserve numerous fossils of land mammals, including early hominin species.  The ridge is being eroded into a badlands terrain by a series of ephemeral rivers that drain into the northeast portion of modern Lake Turkana. 

In 1968 Richard Leakey established the Koobi Fora Base Camp on a large sandspit projecting into the lake near the ridge, which he called the Koobi Fora Spit. A survey and numerous excavations showed the region was a source of hominin fossils from the last 4.2 million years. Far exceeding the number of humanoid fossils are the non-humanoid fossils, which give us a look at the fauna and flora as far back as the Miocene.

In 1973, the government of Kenya reserved the region as Sibiloi National Park, establishing a headquarters for the National Museums of Kenya on Koobi Fora Spit. The reserve is well-maintained and is well-guarded by friendly but armed park police. Protection of sites and especially of wildlife are of prime concern.

Exploration and excavation are done by the Koobi Fora Research Project (KFRP), which collaborates with universities and individuals around the world.

Archaeological sites and artifacts

Archaeological sites
The simple hierarchy of scientific places for Koobi Fora is the following:  Koobi Fora is the region; the region is divided into fossil collecting areas; within fossil collection areas there are archaeological sites and hominid paleontological localities. 

Locating and referencing the hundreds of sites in the Koobi Fora region has been an ongoing process. The entire reservation was divided into somewhat over 100 numbered areas. In the year 2000 the KFRP went over to a GPS system.

Some notable areas are as follows.

Area 105 
The first archaeological site, i.e., FxJj 1, was found in Area 105.  It is nicknamed the KBS site for Kay Behrensmeyer Site, after the researcher who first found stone tools there.  This site is also the place where the first tuff was found, i.e., the KBS Tuff.

Area 131
It is known as the location of skull 1470, discovered by Bernard Ngeneo in 1972, reconstructed by Meave Leakey, later reconstructed and named Homo habilis by Richard Leakey, as possibly the first of the genus Homo, and finally Homo rudolfensis. Richard Leakey found it 45 m below the 1.89 my KBS tuff; thus, it is older than that date, but is conventionally dated to it.

Hominid fossils
Searching for and finding fossils in such a large area is another difficult problem. One solution has been to organize all persons present into a group to sweep a designated area. Richard Leakey devised a method that produced better results: he organized and trained a search team of Kenyans, which became known as "the hominid gang", under the leadership of Kamoya Kimeu. They have discovered the majority of the fossil Hominins, which currently amount to over 200.

Koobi Fora is perhaps best known for its specimens of the genus Homo, but those of the genus Australopithecus also have been found. The following species are represented:

{|class="wikitable"
!Species Name
!Dates(KF only)
!Representative Fossils
!Notes
|+
|-
|Australopithecus anamensis|4.2-3.9 mya
|30731, -44, -45, -50, 35228, -31, -32, -33, -35, -36, -38
|Found at Allia Bay. Earliest evidence of bipedal gait.
|-
|Australopithecus boisei 
|2.1-1.1 mya.
|406, 729, 13750, 23000, 732. 
|
|-
|Homo habilis|1.9-1.6 mya
|1813, 1501, 1502, 1805, 1808.
|Called "habilines" or "hablines". Others have been reclassified from this species to Homo rudolfensis. Habilis is considered the earliest or among the earliest of Homo.
|-
|Homo rudolfensis|1.9-1.6 mya
|1470, 1912, 1590, 3732, 1801, 1802, 1472.
|Rudolfensis may split again to place some fossils, such as 1470, with Kenyanthropus platyops. Rudolfensis also shares the name "habline."
|-
|Homo ergaster|1.8-1.4 mya
|992, 730, 731, 819, 820, 3733, 3883.
|Considered a sort of pre-erectus if not early Homo erectus, from which it was split. Some refer to ergaster as the African erectus.
|-
|}Australopithecus and Homo seem to have coexisted in the region for about one million years. One possible explanation is different food sources. It is believed that Australopithecus became extinct and Homo'' went on to generate later species.

Stone tools
Large quantities of stone tools have been found at Koobi Fora both on the surface and in caches, which have dates of their own, but are seldom in association with hominins. No other candidates for their manufacture have been found, however. The tools are Oldowan and Acheulean. The Koobi Fora community has devised the following teminology to describe three local industries:

With the change from Olduwan to Acheulean technique, hominins got more of a return for a given output of energy and could do more. The chief technological development was the edge of the handax. The advantage of the "core reduction strategy" was more and thinner flakes per mass of cores. More and better flakes meant better use of carcasses and therefore a need for fewer carcasses, less hunting, etc. Moreover, the increased number of flakes available made ranging farther from the source of the stone possible and gave more staying power to the hunt.

Stratigraphy
Koobi Fora is underlain by Pliocene basalts and filled with nearly 600 meters of Pliocene-Pleistocene sediments, dating from about four-million to one-million years ago.

Most early human fossils and archaeological remains come from the upper portion of the Burgi Member, the KBS Member, and the Okote Member.  The members reflect changing environments in the Turkana Basin, from lake and delta ones during Burgi Member times to rivers and floodplains in Okote Member times.

The stratigraphy of the Koobi Fora Formation is one of the best studied and calibrated in East Africa.  Controversial dating of the KBS Tuff during the 1970s helped to spearhead the development of modern potassium/argon and argon/argon geological dating methods.  In addition, the unique fusion between geochronology and mammal evolutionary studies has made the Koobi Fora Formation a standard for all of Pliocene-Pleistocene Africa.

References 

Archaeological sites in Africa
Kenya
Prehistoric Africa