There was a stretch of miles where steep steps in hard red rock
alternated with long levels of round boulders. Here, one by one, the
mustangs went lame and we had to walk. And we slipped and stumbled
along over these loose, treacherous stones. The hours passed; the toil
increased; the progress diminished; one of the mustangs failed and was
left. And all the while the dimensions of Nonnezoshe Boco magnified
and its character changed. It became a thousand-foot walled canyon,
leaning, broken, threatening, with great yellow slides blocking
passage, with huge sections split off from the main wall, with immense
dark and gloomy caverns. Strangely it had no intersecting canyons. It
jealously guarded its secret. Its unusual formations of cavern and
pillar and half-arch led me to expect any monstrous stone-shape left
by avalanche or cataclysm.

Down and down we toiled. And now the stream-bed was bare of boulders
and the banks of earth. The floods that had rolled down that canyon
had here borne away every loose thing. All the floor, in places, was
bare red and white stone, polished, glistening, slippery, affording
treacherous foothold. And the time came when Wetherill abandoned the
stream-bed to take to the rock-strewn and cactus-covered ledges above.

The canyon widened ahead into a great ragged iron-lined amphitheater,
and then apparently turned abruptly at right angles. Sunset rimmed the
walls.

I had been tired for a long time and now I began to limp and lag. I
wondered what on earth would make Wetherill and the Indians tired. It
was with great pleasure that I observed the giant Joe Lee plodding
slowly along. And when I glanced behind at my straggling party it was