Boyce Rensberger

It is a wild and rugged place — hot, dry, uninhabited most of the year and then only by wandering Masai herdsmen tending their ragged cattle. It is called Olorgesailie and it is 100 miles south of the Equator on the floor of Kenya’s Rift Valley, where the earth’s crust cracked open millions of years ago. Ever since, earthquakes have tossed the still widening and subsiding valley floor into a wrinkled and broken landscape. Commanding the scene, five miles to the south, is Mt. Olorgesailie, a dormant volcano peaking half a mile above the valley floor. Fifteen miles to the east is the wall of the Rift Valley, a precipitous escarpment rising nearly 3,000 feet to the flat, more typical East African plains beyond. Here, along one of the gentler slopes of the valley, the infrequent rains have for decades been delicately washing away the soil to expose one of the most remarkable displays of the technology of early man to be found anywhere. Here, lying on the surface of the ground, unrecognized until the