According to a new study published in the Proceedings of the National Academy of Sciences, the oldest mine in America was used to excavate for ochre, the vital pigment used to make paint.

The mine, referred to as the Powars II site by archaeologists, is in the foothills of the Rocky Mountains in Wyoming. There, Indigenous people began quarrying for hematite (the iron oxide compound that produces the red pigment we know as ochre) some 12,840 years ago. The mine was used on and off for an ensuing 1,000 years.

Indigenous peoples used antlers and animal bones to excavate for the hematite. The pigment, once processed, would be used in a variety of rituals, and traces of it can be found in ancient graves, kill sites, and campsites.

This discovery has been a long time coming.

“It’s gratifying that we were finally able to confirm the significance of the Powars II site after decades of work by so many,” said lead author Spencer Pelton in a statement. Pelton mentioned George Frison, who learned of the site in the 1980s and researched the mine until his death in 2020. The work was carried on by Frison’s colleagues and students.

The mine was of incredible importance to the societies of the time, as it was only one of five ochre quarries in all of the Americas, and the only one in North America. As such, it was a key site for the people who once inhabited the area.

“Beyond its status as a quarry, the Powars II artifact assemblage is itself one of the densest and most diverse of any thus far discovered in the early Paleoindian record of the Americas,” Pelton said in his statement.

Powars II will be the subject of an ensuing study of the surrounding area that will try to piece together the lives lived around this important source of pigment.