The Calaveras Skull

On February 25, 1866, workers found a human skull buried deep inside a mine on Bald Mountain in Calaveras County, California. The skull was located 130 feet below the surface, beneath a layer of lava. The owner of the mine, James Mattison, gave the skull to a merchant who in turn passed it on to a local physician until it eventually found its way into the possession of J.D. Whitney, the State Geologist of California and Professor of Geology at Harvard University. Whitney determined that the skull belonged to a Pliocene age man. This made it the oldest known record of human existence in North America. It also suggested that humans had lived in the Americas far longer than previously thought, perhaps as long as they had lived in Europe.

However, the authenticity of the skull was challenged by other scholars. What ensued was a long controversy between those who insisted the skull had been planted at the mine, and those who insisted it was a genuine find.

It took many years before the skull was decisively determined to be a fake. The skull was simply too modern in character to be from the Pliocene age. In addition, the sediment attached to it was not from the mine deposit, indicating it had been planted. The skull was probably planted by miners playing a practical joke.

As early as 1869, a San Francisco newspaper declared, "We believe the whole story worthy of no scientific credence... a minister... told us that the miners freely told him that they purposely got up the whole affair as a joke on Professor Whitney."

Smithsonian scientist W.H. Holmes pointed out that the sediment found with the skull was of a modern type. The skull itself also looked modern. In addition, many scientists were disturbed by the fact that a qualified researcher had not had a chance to examine the skull in situ.

Despite the doubts expressed about the skull, Whitney continued to believe it was genuine. He was eventually replaced at Harvard by F.W. Putnam, who also argued for the skull's authenticity.

By the 1890s the skull was still accepted as genuine by the academic community, but it was becoming obvious that it did not fit into the growing fossil record of man's evolution. So in 1901 Putnam decided to determine, once and for all, whether the skull was authentic.

While in California he did some research and learned that in 1865 a number of Indian skulls had been dug up from a nearby Indian burial site. One of these skulls had been planted in the Bald Mountain mine so that workers would later find it. Despite hearing this story, Putnam was still not ready to declare the skull a fake. Instead he simply conceded that "It may be impossible ever to determine to the satisfaction of the archaeologist the place where the skull was actually found."

To confuse the matter, a careful comparison of the skull with descriptions of the skull at the time it had originally been found, led investigators to conclude that the two were not the same. In other words, at some point between the time that it had been dug up and the time that it had come into the possession of Whitney, the skull had been switched.

It now seems clear that neither the skull found in the mine, nor the skull acquired by Whitney, were genuine ancient skulls. The skulls were simply too modern in character to be from the Pliocene age, and in addition, the sediment attached to them was not from the mine deposit, indicating that they had been planted.

Historian Ralph Dexter concludes, "The desire on the part of miners to play a practical joke, the anxiety of archaeologists to prove the existence of early humankind in North America, the firm convictions and good faith of those involved in an honest mistake, and the confusion resulting from a mix-up of skulls, led to this long drawn-out controversy, unique in the annals of American archaeology."

• Dexter, Ralph W. "Historical Aspects of the Calaveras Skull Controversy." American Antiquity. 51, no.2 (1986): 365-69.

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