The Calico Early Man Site - A Dramatic Trip Through Human and Geologic Time

As we researched what we might do and see in the area east of Barstow, California, we came across references to the Calico Early Man Site, located on BLM lands in the Calico Mountains.

One of the most controversial archaeological sites in the Western Hemisphere, it displays evidence for the presence of tool-making humans in the Americas some 200,000 years ago, far earlier than any Western Hemisphere site that has been accepted by the majority of the archaeological community. The alluvial fan deposits in this area are uniquely deep stratum layers that may represent the oldest evidence of human occupation in the Americas. In 1980, geologists estimated that the soils at this site may date back to over 200,000 years, using a uranium-thorium dating process on the surrounding strata.

The history of this site dates back to 1942, when amateur archaeologists discovered what they believed to be primitive stone tools in this area. Fragments were embedded in the sediments of the shoreline of an ancient Pleistocene Era lake, called Lake Manix.  The Calico site was developed beginning in 1964 with the active involvement of Louis B. Leakey, one of archaeology’s greatest names, famed for his pioneering work on the African Paleolithic at Olduvai Gorge in Tanzania. Leakey, and his son, Richard, are well known for their Early Man discoveries at Olduvai Gorge in east Africa.  This was the only New World archaeology project undertaken by Dr. Leakey.
 
Archaeologists have classified this site as a possible stone tool workshop, quarry, and camp site. Perhaps early nomadic hunters and gatherers stopped in this area to fashion the tools they used to survive. These tools may have included stone knives, scrapers, punches, picks, and chopping tools, as well as some saw-like tools called denticulates. However, because no human bones or remains have be found here, there is quite a controversy about whether these stone objects represent human artifacts, or simply are the result of as-yet-unidentified geologic processes.  Aside from the lack of other corroborating human artifacts (such as bones or other evidence of human activity), the primary reason for the controversy is the apparent age of the site - which dramatically predates the periods of known human habitation in North America.

This was enough to pique our curiosity, and we set out, 3 miles up a rutted gravel road ---

--- to find out more about this archaeological dig.

We arrived at the dig site, which included a visitor center, a building to oversee the archaeological work, and the residence of the site manager:

As soon as we walked up from the truck, the Site Manager, Chris Christensen, an affable man with an engineering background ---

--- strolled up to us and offered to give us an introduction to the site.  He began by showing us examples of the items found at the site, which were displayed in glass cases in the visitor center:

Here is a close-up of some of the items, comparing the items found at more recent geologic levels (the "Manix Lithic Industry") with the more controversial, earlier items (the "Calico Early Man Tools"):

He invited us to take the self-guided walking tour, which took us around the entire site, including all of the pits in which the items have been uncovered.

The investigation of the site was both benefitted and hindered by mining activity that preceded the original discovery.  The site had been the location of a bentonite mine, and the mining pit was clearly evident as we started our tour:

Ironically, however, it was because of the mining pit that the original items were discovered on the site.  The location of the original discovery is marked by a white post planted on the far side of the mine pit:

As geologists and archaeologists became more familiar with the apparent geologic history of the site, they realized that the items originally discovered had probably washed down from the higher surrounding hills.  Our next stop in our hike up the hill was to a bench holding examples of items in the condition in which they were found on the site:

We came to Master Pit No. 1, which was the first of the pits dug at locations suggested by Dr. Leakey:

We had a chance to walk through organized piles of excavated rocks.  To archaeologists and geologists, the rocks forming the matrix in which items are discovered can be as important as the artifacts themselves --- especially where, as here, there is debate about whether these items were formed by geological processes (which presumably would also have affected the surrounding rock) or human activity (which presumably would not have affected surrounding rock in the same way).  The piles of rock were stacked and arranged to identify what section of the pit they had come from:

Here's a view of the pit itself, which measured 25 feet wide, 25 feet long, and 25 feet deep:

Several other pits have been dug using the same process.

We were fortunate to have come to the site on the first Saturday of the month, which is set aside for archaeological work by the professor supervising the site and volunteers who have driven from miles around to help with the work:

The work is supported through nonprofit and charitable contributions, overseen by the Friends of Calico.  Some of the basic information relating to the dig itself is published on the dig's website. The Wikipedia article on the Calico Early Man Site offers a good summary of the questions and criticisms that have been raised regarding the theory that these items were human-manufactured tools.

Having visited the site and looked at the items, we have become believers that this site genuinely represents human activity at a time much earlier than we previously thought humans occupied North America.  It reminds us of Shakespeare's famous line:

There are more things in heaven and earth, Horatio, 

Than are dreamt of in your philosophy. 

- Hamlet (1.5.167-8), Hamlet to Horatio