By the time he was thoroughly convinced that Sandy was going to be hard to stop, Sandy had topped the rise and was streaking it across an expanse of barrenness that rose gently in spite of the fact that it looked perfectly level.

A sliding streak of gray dust rising into the heat waves marked his passing.
Nearly a mile he ran before the slight grade and a rocky strip slowed him down to a heavy gallop.

Johnny had been in the mind to let the fool run himself down just for punishment, but the rocks and an eagerness to return to the stranded plane urged him to forego the discipline.
He stopped just where the scattered rocks ended abruptly in a wall that rimmed a sunken, green valley, narrowing near where Johnny stood looking down, but broadening farther along, and seeming to extend southward with many twistings and windings.

Johnny viewed the place with a passing surprise, familiar though he was with the freakish topography of Arizona.
It was the greenness, and the little winding creek, and the huddle of adobe buildings among the cottonwoods that struck him oddly.

The creek might be a continuation of Sinkhole Creek, that disappeared into the sands away back there near his camp.