cific Ocean instead of the Gulf of Mexico. The drainage
was changed by the work of a small stream having its source in
the volcanic plateau north of the lake. It deepened its channel
and extended its head waters back until they tapped the lake at
a point where the rim of the basin was lowest, and so drew away
its waters in the opposite direction. The Yellowstone River, with
its deep, wondrously colored canon and grand waterfalls, is the
result of this change.

[Illustration: FIG. 132.--ECONOMIC GEYSER, YELLOWSTONE PARK]

To the south of Yellowstone Park, but included in one of the forest
reserves, are Jackson Lake and the Teton range. The Three Tetons,
one of which reaches a height of over thirteen thousand feet, were
evidently noted landmarks for the hunters and trappers in the early
days, for you will find them mentioned in many of the narratives of
those times. The precipitous range, with its crown of jagged peaks
and the beautiful lake nestling at its base, presents a picture
never to be forgotten.

Very different from the region which we have been studying is that
embracing the Crater Lake, National Park, which is situated upon
the summit of the Cascade Range in southern Oregon. Here occurred,
not many thousand years ago, one of the strangest catastrophes
which, so far as we know, has ever overtaken any portion of our
earth.

Towering over the present basin of Crater Lake was a great volcano,
reaching, probably, nearly three miles toward the sky. During the
glacial period it stood there, its slopes white with snow, apparently
as strong and firm as Shasta or Hood or Ranier. But for some reason
the volcanic forces within this mountain, which has been called
Mazama, awoke to renewed action. The interior of the mountain was
melted, and the whole mass, unable to stand longer, fell in and
was engulfed in the fiery, seething lava. This lava, instead of
welling up and filling the crater and perhaps flowing out, was
drawn down through the throat of the volcano into the earth, and
left an enormous pit or crater where once the mountain stood.

After the floor of the crater cooled and hardened, small eruptions
occurred within it and a new volcano grew up, but, though nearly three
thousand feet high, it does not reach to the top of the encircling
walls of the old crater, which are, on an average, nearly four
thousand feet high.

Then the rains and melting snows formed a body of water in the
crater, and the wonderful la