The site is believed to have been a lake about 180,000 years ago. However, because of volcanic activity, the lake has since disappeared. Over time, rain and wind eroded the sediment and buried traces of animal and human activity deep beneath the surface.
Several sites used for butchering animals, marked by a concentration of hand axes, other stone tools, and bone fragments of extinct animals deposited more than 100,000 years ago have been discovered.
Opuka says the lake once attracted wild animals, including extinct species of hippo, zebra, elephant, baboon, and giraffe.
Fossils indicate that large baboons and zebras were especially abundant in Olorgesailie between 1 million and 700,000 years ago. Many of these species probably became extinct around 300,000 years ago.
To protect the archaeological and paleontological materials from both human interference and natural degradation, a raised wooden platform has been constructed. This allows visitors to explore the site without disturbing the remains.
