Near Langtry, Texas, in January 2017, the Texas Archeological Society hosted the Lower Pecos Canyonlands Academy. It was an immersion in new research into Texas prehistory.

One focus of that research is Eagle Cave. The cave, deep in a canyon near the Rio Grande, attracted human communities for 13,000 years. Sediments accumulated through human use, and those sediments preserve tools and bones, traces of plant foods, ancient latrines.

What does this site have to tell us? And what does research here entail?

“In 1935, 36, the Witte Museum did the first large-scale excavation at Eagle Cave,” archeologist Charles Koenig said, “and they dug what became this trench...”

The limest...