n Buck Tooth working
unusually hard in addition to doing the cooking. Though Indian braves
are constitutionally opposed to labor, Buck Tooth made an ideal
herdsman.

Not as much time was spent in camp as had formerly been the case, as
the boy ranchers and their older helpers were more often out riding
herd. But occasionally many of them gathered at the tents to compare
notes and "feed up," as Snake put it. His wound, received in the fight
with the rustlers, had healed.

"Some day we'll have regular ranch houses here instead of just a camp,"
Bud said, as he was riding back one day to look after the herd he had
assigned to himself.

"Oh, this isn't so bad," spoke Nort.

"Real jolly, I call it!" added Dick.

"If only the water supply keeps up, and no more epidemic comes, we'll
be all right," Bud announced. "At the same time I can't be sure of
either."

This was true. Though the water flowed merrily on since the time the
lads had penetrated the length of the tunnel, there was always an
uneasy feeling, on the part of the boy ranchers and their friends, that
it might stop at any time.

"And when it dries up again," Bud declared, "I'm not going to be
satisfied until I find out what makes it quit flowing!"

"That's the idea!" added Nort. "We'll solve the mystery!"

As the days passed, and no more cattle were found ill or dead from the
epidemic, the hopes of the boy ranchers began to rise. Had they caught
the malady in time? Could it be stamped out by the burial of the five
steers? Time alone--and a longer time than had so far elapsed--could
tell.

Bud, Nort and Dick each had charge of a herd, the three bunches of
cattle being pastured on adjoining areas of rich grass.

But the distances separating them were not so great but that Bud and
his cousins could exchange visits. And it was on one of these
occasions that there occurred something which cleared up, in part at
least, the mystery hanging over Flume Valley.

The boy ranchers were about to part for the evening, having spent the
afternoon together over "grub," cooking at an open fire; and Nort and
Dick were preparing to ride back to their herds, Bud being on the
ground, so to speak, where he would "bunk" for the night.

As they rode down into a little swale amid the gathering shadows of the
night, a bunch of cattle moved uneasily along ahead of them, and as the
steers parted there was disclosed in their midst the forms of a man and
a horse.

"Who'