Fire exposes something really interesting on Montana’s plains – an unseen stone complex. reveals what we now know about the ceremonial carvings hidden for centuries under the sod:

Among the formations are two large effigies — or figures made from arrangements of stones — one of a human and the other, perhaps, of a turtle.

The burn also exposed six rock cairns, a multitude of stone tipi rings, and dozens of so-called drive lines — alignments of large boulders that ancient hunters used to chase bison into a killing pen.

The artifacts — along with radiocarbon dates from six discrete layers of cast-off bison remains — showed that the site was used regularly from 770 to 1040 CE.

As part of a new test project this spring, land managers set out both to preserve and to record the Henry Smith site, using a combination of the very latest technology, and the most ancient.

First, in mid-April, a prescribed fire was set and was allowed to consume some 320 acres of open prairie.

Then, two weeks later, officials surveyed the blackened area using an aerial drone, flying at a height of 90 meters to create the first three-dimensional map of the site, and likely revealing the full extent of its features for the first time in centuries.

“Removal of the vegetation allowed for a clear view of an Avonlea period cultural resource complex, consisting of numerous stone effigies — both anthropomorphic and zoomorphic — stone cairns, drive lines, stone circles and potentially spiritual alignments and circles,” said Josh Chase, archaeologist for the U.S. Bureau of Land Management

[via Archaeological News]