ctor, bound to look into the secrets of Thunder
Mountain as we're bent on doing; only he hunts for gold, while we're
just bent on finding things out."

"But look now," Frank said a little later, as the other came closer.
"Don't you see that it's only a little Mexican boy on that bag of bones
of a horse? Tell you what, Bob, he must have been sent to town for
fresh supplies by some party of gold hunters located right now over the
range."

"Yes, and how do we know but what this Mexican boy is hooked up with
that Mendoza crowd?" asked the other, seriously. "They might send him
off for grub, and such things as they happen to need. And he pays for
it with money they get from selling stolen cattle and horses! Nobody
would suspect him, Frank, and try to follow. I hope our horses don't
give us away now. I'd like to see what that little fellow does."

The boy indeed looked weary as he drew closer, leading his tired burro,
upon which a fair-sized load was strapped and roped.

"Get down, Bob," said Frank. "He hasn't glimpsed us, and, luckily
enough, our horses are feeding out of sight just now. Doesn't he look
sleepy and tuckered out though? See him nodding in his saddle, poor
little runt! Oh! what's that moving there among those rocks just
ahead?"

"Perhaps it may be one of the rustlers coming down to interview him,"
said Bob.

"Hist!" Frank uttered almost in his chum's ear as he craned his own
neck in order to see better.

The small boy on the tired broncho, and leading the patient burro, kept
on steadily advancing, apparently allowing his animal to follow its
nose, as though it knew the way fairly well from having passed along it
before.

"Look! look!" ejaculated Frank suddenly, jumping to his feet. "Great
guns! Bob, would you see what is coming out from among those loose
rocks there? A great big grizzly bear; and making straight for the
pack mule, sniffing the air as if he smelled grub! There, the horse
has scented him. See him rear up, will you? Oh! he's gone and done
it, as sure as you live--thrown the boy over his head! And the poor
burro is caught fast, with his leading rope held in a crotch of the
rocks. The boy will be killed if ever he meets up with that monster!
Quick! We must do something to save him, Bob, but whatever shall it
be?" and Frank leaped to his feet.

CHAPTER VIII

A STARTLING DISCOVERY

The Mexican boy had apparently escaped serious injury at the time the
frightened