And he made several miles of up-and-down progress over this rough plateau.

The great walls of the opposite side of the canyon loomed appreciably closer.

What, Slone wondered, was at the bottom of this rent in the earth?
The great desert river was down there, of course, but he knew nothing of it.
Would that turn back Wildfire?
Slone thought grimly how he had always claimed Nagger to be part fish and part bird.

Wildfire was not going to escape.
By and by only isolated mescal plants with long, yellow-plumed spears broke the bare monotony of the plateau.

And Slone passed from red sand and gravel to a red, soft shale, and from that to hard, red rock.