Bob; and saddling up, with packs in
place, the boys soon left the scene of their night bivouac, heading
toward the heavy growth of timber directly at the foot of the mountain.

The early morning mists concealed their movements until they had
entered among the timber; when they left they were safe from any
suspicious eye, should the bold Mexican rustler have posted any watcher
upon the side of the mountain.

Again did the saddle boys build a small fire in a hole, over which they
proceeded to cook their breakfast; while the horses cropped the grass
near by, secured by the ever useful lariats, or riatas.

"There's where this leads into a big gully," remarked Bob, later on,
pointing as he spoke to where the ground became broken.

"Yes," Frank went on, thoughtfully, "and the chances are ten to one
that it changes into a regular canyon, where the water rushes down
whenever they have one of those gushers, or cloud bursts, that come
along once in a while around here. Now, I wonder if those riders hit
it up this way?"

He jumped to his feet as he said this. Passing back and forth, Frank
seemed to be examining the ground, marking the stepping stones of the
mountain.

"Signs aplenty around here," he remarked. "Wish old Hank was along to
read 'em. I reckon I can tell what they stand for, though."

"Then they went on up that canyon, you believe?" asked Bob.

"Reckon there isn't any doubt about that part of it," chuckled Frank;
"though just where that same canyon leads I can't say. P'raps it may
be a short-cut across the big range here, leading to the prairie on the
other side. P'raps it doesn't go anywhere, but just leads to a blind
hole that I've heard prospectors call a _cul de sac_. Anyhow, we ought
to find out, Bob."

"_They_ knew all right," remarked the other, positively. "Wouldn't get
any riders going up there in the dark, unless they were mighty familiar
with every foot of the way. That's my idea, Frank."

"And I reckon it's the true one," asserted the other. "They know this
place as well as I do all around old Circle Ranch."

"There's the sun coming up; and perhaps we'd better be getting a move
on about now?" suggested Bob.

"Wait!"

Something in the tone which his saddle chum used caused Bob to turn his
head, and look out toward the plain.

"Huh! what does that mean?" he ejaculated. "A single rider heading
this way; and he seems to be leading a burro loaded with supplies.
Must be a bold prospe