enough," Frank remarked, looking up at the
dimly-seen outlines of the far-away crest of the rocky elevation, where
it stood out against the starry heavens.

"You don't believe, then, that there could have been some kind of storm
up there; do you?" questioned Bob.

"Well, it's sure a great puzzle," replied his chum, with a long breath.
"My eyes are reckoned prime, but I can't glimpse any sign of a cloud
that would bring out all that noise. A mystery it's been these many
years; and if so be we can learn the cause for all that queer roaring
that shakes the earth, we'll be doing more'n anyone else has ever done
in the past."

"That's what we're here for, if Peg gives us half a chance," remarked
Bob, with the healthy assurance of youth. "And as neither of us takes
any stock in the fairy story about the Manitou's anger, we ought to
stand some chance of locating the thing; or 'bust the b'iler trying' as
old Hank would say."

Frank had crawled out of his blanket, and stood erect.

"What's on?" asked his camp-mate, presently, noticing that he was
holding up his hand, after wetting his finger, a method much in vogue
when one wished to learn the direction of the passing air currents.

"Southeast; and blowing strong a bit ago up there on the mountain, I
reckon," Frank remarked. "You notice we happen to be sheltered more or
less down here, when she comes out of that same quarter?"

"Meaning the wind," Bob remarked. "Yes, you're right, Frank. But what
has that got to do with the measly old grumble of the mountain, tell
me?"

"Huh! I don't know that it's going to have anything to do with it,"
came the answer; "but we want to know every little point as we go on.
And Bob, just remember that the wind was coming out of the Southeast;
and a clear sky overhead!"

"But look here, Frank, you've heard your dad talk about this Thunder
Mountain business, I take it?"

"Well, now, I reckon I have, heaps of times; but then you know, he
isn't much on bothering about things that don't concern him. Thinks
he's got his hands full, looking after the stock, keeping tabs on the
doings of those rascally Mexican rustlers, that have been running off
batches of cattle every little while; and fighting that big syndicate
of Eastern capitalists, headed by the millionaire, Mr. Grant, Peg's
father, that wants to throw all the Southwestern ranches into a close
trust."

"But what I wanted to remark is this: you must have heard him give an
opin