Bedrock surface on the upland-canyon edge on the Hinds Ranch. As recently as the early 20 th century there was still enough soil present along the canyon edge to make horseback riding possible. Today these surfaces are largely denuded, a process which sometimes brings archeological evidence to light. In the foreground are several stone tools classified as “formal unifaces” that functioned as knives for trimming plants such the clumped up sotol visible in the background. Photo by Joe Saunders.