re streams of white dust to be seen, streaks of yellow dust,
trailing low clouds of sand over the glistening dunes, but no steadily
rising, uniformly shaped puffs that would tell a tale of moving horses
on the desert.

At noon the rangers got out of the thick cactus. Moreover, the
gravel-bottomed washes, the low weathering, rotting ledges of yellow
rock gave place to hard sandy rolls and bare clay knolls. The desert
resembled a rounded hummocky sea of color. All light shades of blue
and pink and yellow and mauve were there dominated by the glaring white
sun. Mirages glistened, wavered, faded in the shimmering waves of
heat. Dust as fine as powder whiffed up from under the tireless hoofs.

The rangers rode on and the escarpment began to loom. The desert floor
inclined perceptibly upward. When Gale got an unobstructed view of the
slope of the escarpment he located the raiders and horses. In another
hour's travel the rangers could see with naked eyes a long, faint
moving streak of black and white dots.

"They're headin' for that yellow pass," said Ladd, pointing to a break
in the eastern end of the escarpment. "When they get out of sight
we'll rustle. I'm thinkin' that waterhole the Yaqui spoke of lays in
the pass."

The rangers traveled swiftly over the remaining miles of level desert
leading to the ascent of the escarpment. When they achieved the
gateway of the pass the sun was low in the west. Dwarfed mesquite and
greasewood appeared among the rocks. Ladd gave the word to tie up
horses and go forward on foot.

The narrow neck of the pass opened and descended into a valley half a
mile wide, perhaps twice that in length. It had apparently unscalable
slopes of weathered rock leading up to beetling walls. With floor bare
and hard and white, except for a patch of green mesquite near the far
end it was a lurid and desolate spot, the barren bottom of a desert
bowl.

"Keep down, boys" said Ladd. "There's the waterhole an' hosses have
sharp eyes. Shore the Yaqui figgered this place. I never seen its
like for a trap."

Both white and black horses showed against the green, and a thin
curling column of blue smoke rose lazily from amid the mesquites.

"I reckon we'd better wait till dark, or mebbe daylight," said Jim Lash.

"Let me figger some. Dick, what do you make of the outlet to this
hole? Looks rough to me."

With his glass Gale studied the narrow construction of walls and
roughened rising floor.