a portion of the valley.

Now followed a long period of quiet. Trees began to grow upon the
sand and gradually to encroach upon the barren wastes about Cinder
Cone. It appeared as if there were to be no more eruptions. But
the volcano was only resting. At about the time, perhaps, when
the gold seekers began to pour across the continent to California,
there was another eruption; but this time it took the form of a
lava flow and was so quiet as to create no disturbance in the
surrounding country.

[Illustration: FIG. 28.--CINDER CONE

The trees were killed by the last eruption of volcanic ashes]

A stream of thick, viscous lava flowed slowly out of an opening
at the southern base of Cinder Cone. As the lava crept down the
gentle slopes of the valley, it crusted over, forming a black,
slag-like surface. The surface was from time to time broken up
and mixed with the softer portions beneath, so that the movement
of the flow was still further retarded. At the lower end of the
valley the lava occupied a portion of a body of water now known
as Lake Bidwell; its rugged front made a dam across the valley
above, forming Snag Lake. The stumps of the trees which were killed
by the water when the lake was first formed are still standing.

[Illustration: FIG. 29.--THE LAST LAVA FLOW IN THE UNITED STATES

At Cinder Cone, California. It formed a dam across a valley, thus
creating Snag Lake]

One's feet sink deep into volcanic sands, and walking is tiresome.
The lava field resulting from the last eruption is free from sand,
but its rough surface, formed of broken blocks, is difficult to
cross.

A few charred stumps rise out of the sand, pathetic remnants of the
forest trees that were growing at the time of the first eruption.
Most of the trees have completely disappeared, leaving shallow
pits where they once stood.

It is exceedingly difficult to climb the cone, which rises over
six hundred feet, for the slopes, composed of loose lapilli, are
so steep that one slips back at every step nearly as far as he
advances. From the summit a remarkable sight meets the eye. Within
the rim of the main crater is a second crater with a rim nearly as
high as the first, while the cavity within has a depth of about
two hundred and fifty feet.

Because of the loose character of the material of which it is built,
no streamlets have yet worn channels down the slopes of Cinder
Cone, and except for the presence of two small bushes which cling
t