Editing Louis Leakey (section)

===Calico Hills===
{{Main|Calico Early Man Site}}

In 1959 Leakey, while at the [[British Museum of Natural History]] in London, received a visit from [[Ruth DeEtte Simpson]], an archaeologist from California. Simpson had acquired what looked like ancient [[Scraper (archaeology)|scraper]]s from a site in the Calico Hills and showed it to Leakey.

In 1963, Leakey obtained funds from the [[National Geographic Society]] and commenced [[archaeological excavation]]s with Simpson. Excavations at the site carried out by Leakey and Simpson revealed that they had located stone [[Artifact (archaeology)|artifacts]] which were dated 100,000 years or older, suggesting a human presence in North America much earlier than others had estimated.<ref>Cameron B. Wesson, ''Historical Dictionary of Early North America'', 2005, p. 35.</ref>

The geologist [[Vance Haynes]] had made three visits to the site in 1973 and had claimed that the artifacts found by Leakey were naturally formed [[geofacts]]. According to Haynes, the geofacts were formed by stones becoming fractured in an ancient river on the site.<ref>Steven Mithen, ''After the Ice: a global human history, 20,000–5000 BC'', 2006, p. 540.</ref>

In her autobiography, [[Mary Leakey]] wrote that because of Louis's involvement with the Calico Hills site she had lost academic respect for him and that the Calico excavation project was "catastrophic to his professional career and was largely responsible for the parting of our ways".<ref>Mary Leakey, ''Disclosing the past'', 1984, pp. 142–144.</ref>