YERMO, Calif. — Once a month, small groups of men and women gather near this small Mojave Desert town to carry on the meticulous, methodical tasks of an archeological dig begun more than 25 years ago by famed fossil-finder Louis Leakey.
Working out of deep, vertical pits on the slopes of a mountain and using dental picks, ball peen hammers, tiny brushes and trowels, the excavators have dug up literally tons of small rocks. In the process, they have become part of a scientific dispute.
A few scientists believe the rocks are prehistoric tools manufactured 200,000 years ago, which would make them the earliest indication of man's presence in the Western Hemisphere.
But other scientists scoff at that theory, saying the unusual shaping of the rocks is the result of natural causes.
Still others are willing to concede that the rocks are man-made tools, but nowhere near the age claimed.
Most anthropologists believe that the first humans migrated to North America 10,000 to 12,000 years ago.
Other than the rocks with sharp edges, no other evidence of early man's presence has been unearthed at the site--no skeletal remains, no projectile points, no tool handles.
The five-acre dig area has been named the Calico Early Man Archeological Site and is on the National Register of Historical Places. It is 140 miles northeast of Los Angeles in the arid desert north of Interstate 15 and is on land administered by the U.S. Bureau of Land Management.
About 60,000 small rocks, each believed by archeologist Ruth DeEtte (Dee) Simpson, 71, to show some evidence that man shaped them, are stored in hundreds of boxes in the basement of the San Bernardino County Museum in Redlands.
Each box is labeled as to the type of tool. There are scrapers, boring tools, picks, axes, anvils, hammer stones, cutting implements; 60 different types in all.
"We have about 1,000 really good pieces, tools of mint quality," Simpson, the project director, said as she placed several of the best examples on a table in the basement storage area and laboratory.
Every Tuesday for almost as many years as the dig has been going on, a dozen volunteers spend eight hours sorting, classifying and analyzing rocks recently unearthed from the pits.
Simpson, curator of archeology at the San Bernardino County Museum from 1964 to 1982 who now is curator emeritus, has been involved in the Calico Early Man dig since its inception.
