Palaeo-Indian red ochre quarry identified as the earliest known mine in America

Radiocarbon analysis of well-preserved bison bone fragments revealed the earliest phase of red ochre mining began as far back as 12,840 years ago.

Investigations at the Palaeo-Indian quarry site of Powars II, located in the foothills of the southern Rocky Mountains in eastern Wyoming, have unearthed evidence confirming that red ochre extraction began there nearly 13,000 years ago, making it the earliest documented red ochre mine in the Americas, and very possibly the earliest known mine of any kind on the continent.

University of Wyoming Ph.D. student Chase Mahan studies an artefact from the Powars II archaeological site. IMAGE: Spencer Pelton.

Research at Powars II first began in 1986 when excavations under archaeologist Dr George Frison uncovered Palaeo-Indian artefacts associated with red ochre quarrying.

It is the only red ochre quarry site identified in the archaeological record situated north of Mesoamerica.

Red ochre fulfilled both sacred and profane functions in North American Palaeo-Indian societies, from use in human burials to hide tanning.

These latest investigations, the findings of which have been published in the Proceedings of the National Academy of Sciences, were carried out from 2017 to 2020 and led by Wyoming state archaeologist Spencer Pelton with the assistance of researchers from the University of Wyoming.

The team dug a 6x1m trench, bisecting a previously undocumented quarry feature, which revealed several thousand artefacts of animal bones and antlers relating to two distinct periods of occupation.

The first stratigraphic component contained a diverse assemblage of stone and faunal remains associated with the Clovis and Plainview cultural complexes, and indicative of use in red ochre quarrying and bone tool production and repair.

This complete Clovis point was recovered from the Powars II site.
IMAGE: Spencer Pelton.

Radiocarbon analysis of well-preserved bison bone fragments revealed this earliest phase of mining began around 12,840 to 12,505 years ago.

According to the paper’s authors, ‘the temporal relationship between Clovis and Plainview at Powars II is currently unclear, but it is likely that Clovis slightly predates Plainview given their known temporal relationship elsewhere.’

Their findings suggest Powars II was then abandoned for a brief period, approximately a century, before being quarried by the Hell Gap cultural complex c.11,600 years ago, as indicated by the presence of associated chipped lithics.

‘Beyond its status as a quarry, the Powars II artefact assemblage is itself one of the densest and most diverse of any thus far discovered in the early Palaeo-Indian record of the Americas,’ said Mr Pelton.

‘The site contains over 30 chipped stone tools per square meter, some of the oldest canid remains from an American archaeological site and rare or unique artefacts, among other distinctions.’