West of the Arros River stretches out the immense Mesa de los Apaches, once a stronghold of these marauders, reaching as far as the Rio Bonito.

The plateau is also called "The Devil's Spine Mesa," after a high and very narrow ridge, which rises conspicuously from the mesa's western edge and runs in a northerly and southerly direction, like the edge of a gigantic saw.

To our amazement, the guide here indicated to us where the camino real from Nacori passes east over a gap in the "Devil's Spine" ridge, and then over several sharp buttes that descend toward the mesa.

An odd-looking mesa lay between Rio Bonito and Rio Satachi.

Farthest to the west were the big hogbacks near Nacori, standing out ominously, like a perpetuated flash of lightning.