Bering Sinkhole, in the limestone interior of the Hill Country, sits hundreds of miles from the nearest coast.

The shells found with its ancient burials could only have arrived through long-distance trade or travel.

The specific types of shells found in Texas Archaic burials have been analyzed to identify their geographic origins.

Some come from the Gulf of Mexico coast of Texas.

Others, more surprisingly, come from the Pacific coast — suggesting exchange networks that reached across the entire breadth of the continent.

Shell was not merely a decorative material.