Finding a spot where prehistoric man camped, worked, played, or died usually comes about by accident.
Most sites are found by construction crews, say, or by amateur bone collectors who might notify a local newspaper or university that they have found something out of the ordinary.
Usually the object is an elephant or buffalo bone, too huge to have come from a cow, or an ancient looking stone arrowhead. Professionals may then find a prehistoric site when they excavate the area. Since most of the evidence of early man has been covered over by 10,000 to 2 million years of dust and civilization, the clues to finding such a doorway into the past are hard to come by.
“It’s very hit or miss,” says anthropologist Dennis Stanford of the Smithsonian Institution in Washington, D.C. “If it’s under a parking lot, you’re not going to find it.”
There are a few ways of looking for sites besides relying on blind chance, however. Aerial photographs of a region can lead to important discoveries. The thing to watch for, according to Stanford, is water. People and animals must drink to stay alive, and early man had to camp and live near a water source. Tools, bones, and artifacts of all kinds turn up along the ancient banks of rivers and lakes.
In the Olduvai Gorge in eastern Africa, for example, the late Dr. Louis B. Leakey found several skulls and jawbones that proved that man as a species had been on the earth for more than a million years; the australopithecines, as he called them, had apelike faces, but walked upright in manlike fashion and had large brains.
Dennis Stanford’s main interest is early North American peoples, who were much more recent than australopithecines and physically indistinguishable from modern man.
Near a Texas riverbed Stanford found tiny shards of flint that he thinks were ground off by a prehistoric tool maker while sharpening a stone blade. There were no natural sources of flint in the area, so the stone must have been brought to the site and ground by someone for a specific purpose. Stanford believes the geologic layer in which the shards were lying is 12,000 years old.
Passes through mountains are also likely spots to dig for evidence of early man, since any people who lived in the region probably traveled that way frequently and may have left behind some sign of their presence.