Tafoni are the holes. The word comes from Corsica, where granite cliffs are riddled with them, but the sandstone of the Colorado Plateau and southern Nevada has some of the finest examples anywhere. Once you learn to see them, you notice them on every wall.
How a hole starts
Water carrying dissolved salt seeps into the rock. As it evaporates near the surface, salt crystals grow between the sand grains and push them apart. A few grains fall, the surface roughens, the spot stays shadier and damper than the rock around it, and the process speeds up. The hole feeds itself.
Old or young?
- Young pockets are shallow, with sharp rims and loose sand on the floor.
- Mature pockets have overhanging roofs and a hard, darker crust on the outside.
- The oldest merge into caves — the ones big enough to sit in at Valley of Fire.
Look, do not touch
The thin walls between pockets break easily. Photograph them, then keep your hands on solid rock.
The hole feeds itself — that is the whole secret.
