PTER 6.

THE WHITE MUSTANG

For thirty miles down Nail Canyon we marked, in every dusty trail and
sandy wash, the small, oval, sharply defined tracks of the White
Mustang and his band.

The canyon had been well named. It was long, straight and square sided;
its bare walls glared steel-gray in the sun, smooth, glistening
surfaces that had been polished by wind and water. No weathered heaps
of shale, no crumbled piles of stone obstructed its level floor. And,
softly toning its drab austerity, here grew the white sage, waving in
the breeze, the Indian Paint Brush, with vivid vermilion flower, and
patches of fresh, green grass.

"The White King, as we Arizona wild-hoss wranglers calls this mustang,
is mighty pertickler about his feed, an' he ranged along here last
night, easy like, browsin' on this white sage," said Stewart. Inflected
by our intense interest in the famous mustang, and ruffled slightly by
Jones's manifest surprise and contempt that no one had captured him,
Stewart had volunteered to guide us. "Never knowed him to run in this
way fer water; fact is, never knowed Nail Canyon had a fork. It splits
down here, but you'd think it was only a crack in the wall. An' thet
cunnin' mustang hes been foolin' us fer years about this water-hole."

The fork of Nail Canyon, which Stewart had decided we were in, had been
accidentally discovered by Frank, who, in search of our horses one
morning had crossed a ridge, to come suddenly upon the blind, box-like
head of the canyon. Stewart knew the lay of the ridges and run of the
canyons as well as any man could know a country where, seemingly, every
rod was ridged and bisected, and he was of the opinion that we had
stumbled upon one of the White Mustang's secret passages, by which he
had so often eluded his pursuers.

Hard riding had been the order of the day, but still we covered ten
more miles by sundown. The canyon apparently closed in on us, so camp
was made for the night. The horses were staked out, and supper made
ready while the shadows were dropping; and when darkness settled thick
over us, we lay under our blankets.

Morning disclosed the White Mustang's secret passage. It was a narrow
cleft, splitting the canyon wall, rough, uneven, tortuous and choked
with fallen rocks--no more than a wonderful crack in solid stone,
opening into another canyon. Above us the sky seemed a winding, flowing
stream of blue. The walls were so close in places that a horse with
pack wo