But some of them held, or may still hold, the remains of the people who lived in these hills thousands of years ago.

The limestone country does not give up its secrets easily.

The scrubland is dense, the terrain is rough, and the sinkholes are easy to miss if you do not know what you are looking for.

But the archaeologists who have surveyed this landscape have found enough to know that the Bering Sinkhole is not unique — that the pattern of sinkhole burial extends across the plateau, marking the landscape with the evidence of ancient communities and ancient beliefs.

The Guadalupe River, cutting south from the Hill Country toward the coastal plain, is still a beautiful river — clear water over limestone gravel, lined with cypress and pecan and sycamore.