idently an unusually dry season. Still,
Grenfell spoke of a mile or two of water. Where has it gone?"

"That," explained Devine, "seems the simplest thing of all. Anyway,
I'll give you my theory. When I crawled along the edge of the willows
this afternoon, I found the outlet of an old creek and a beaver-dam.
Now we're assuming that the creek I've mentioned once ran into the
lake just here, that is, before a snowslide filled up the ravine with
debris and diverted the creek into the other gully, the mouth of which
is--below--the beaver-dam."

"You have explained how the water got here, not how it got away," said
Weston, impatiently.

"No," replied Devine. "I haven't explained either of them yet; but
we'll get on a little. Once, and I don't think it was very long ago,
there was a little water with a creek flowing out of it in this
hollow. A colony of beavers came along and put up their dam across
that creek, and that backed the water up a foot or two. If you'd
skirted this hollow you'd have seen that it's tolerably level, and a
foot rise would spread the water quite a way. I want to say that it
was probably a swamp with only grass on it when the creek ran through
it. Well, the beavers liked the place, and piled up their dam, while
the water went farther and farther back across the swamp. Finally, the
beavers either died off or something drove them out. It was probably
after that that the dam broke down and the water ran off. Then the
snowslide cut off the creek, and as the hollow dried out the willows
spread across it."

Weston could find no fault with this train of reasoning, which made
comparatively plain Grenfell's long and unsuccessful search.

"Yes," he admitted, "it's logical, and I think it's correct. I
believe, from what Grenfell once said, that he crossed the range to
the east of us, not far away, some years ago with another man, and he
must have noticed this valley. Further, I now feel reasonably sure
that he and I once stood on the shoulder of the big peak in the
southwest and looked right up the hollow." He smiled rather grimly.
"We naturally saw nothing. We were looking for a lake that had dried
out."

He lay still for a minute or two, and then broached the subject that
both had held in abeyance.

"Well," he said, "what's to be done?"

"Stay here two days," advised Devine. "Gather up a load of specimens
and try to trace the vein. Then we'll put in our stakes, and start
right off for the settlement,