The Femur In The Rock Crusher

It was January 17, 1989, and a crew from the Buhl Highway District was operating a gravel quarry in Twin Falls County, south-central Idaho, about 2.5 kilometers north of the small agricultural town of Buhl.

The Snake River Plain stretches south of this area toward the canyon — a landscape built from ancient lava flows and reshaped by catastrophic floods, including the Bonneville Flood that raced through this corridor roughly 17,400 years ago, depositing the enormous gravel bars that quarry operators have been mining ever since.

The gravels are commercially valuable.

They are also, it turns out, an archive of what happened here at the end of the Pleistocene epoch.

A worker noticed something in the screen of a rock crusher.

It was a bone.

A right femur — a thigh bone — still in one piece, which was remarkable given that it had just survived contact with machinery designed to reduce stone to aggregate.

The crew stopped work immediately.

Someone contacted the Herrett Center for Arts and Science at the College of Southern Idaho in nearby Twin Falls.

Within hours, archaeologists and representatives from the Idaho State Historical Society were at the site.

What they found when they reached the exposed bank had already been significantly compromised.

Gravel quarrying had removed somewhere between two and four meters of the original sediments overlying the burial.

The deposits that had once covered the skeleton were gone, along with whatever contextual information they might have held.

But what remained in the eroding bank was remarkable enough.

The imminent collapse of the profile — the height of the unstable sediments, softening in the afternoon thaw — meant there was no time for standard excavation procedure.

They could not remove the overlying material carefully and work downward in controlled layers.

They had to move fast, working against the clock and against a bank that could close off access to the burial at any moment.