great trees of California of
our day then flourished in Greenland, Iceland, and Western Europe. The
cypress of the Southern States was then growing in Alaska and other high
northern latitudes. The climate probably passed from a tropical one, in
early Tertiary times, to a milder or temperate one in Pliocene times.
Amongst the animals inhabiting America were three species of camels.
Rhinoceroses, mastodons, and elephants trooped over the land. Tigers and
other carnivore prowled in the forests. Herds of horse-like animals, one
scarcely distinguishable from our common horse, grazed in the valleys,
along with several species of deer. From the presence of the old
drainage beds, we know that majestic rivers rolled their watery burden
through the land. Such a country might well afford a home for man if he
were present.

To understand fully the course of events which now took place we must
venture on geological ground. The great Pacific Ocean, lying to the
west of America, is constantly exerting a lateral pressure, which during
Tertiary times showed its effect in the uplifting of the great mountain
ranges of the western coast.<2> During late Tertiary times, as a
counterpart to the upward movement, a great subsidence commenced in
the Pacific region.<3> Doubtless many islands, some think an entire
continent even, disappeared beneath the waves. The completion of the
various mountain ranges left the coast firm and unyielding; hence, as
it could not bend before the fiery flood forced upward from below by the
downward motion just mentioned, it broke, and the torrent of molten rock
leaped out as a lava flow. In consequence of this, near the close of
Pliocene times, the surface of California and Oregon, especially the
north of California, became buried under the lava and ashes of the most
desolating volcanic outbreak that the earth has ever known.

Let us now see what bearing this has on the question of the antiquity of
man. Scattered here and there throughout California are numerous masses
of basaltic lava, which appear as elevated ridges, the softer strata
around having been denuded away. They have received the general name
of Table Mountains. They have not only been noted for their picturesque
beauty, but miners long since found that the gravels underneath the lava
covering were rich in gold. In Tuolumne County the Table Mountain is a
flow of lava which originated in lofty volcanoes several miles away.

It extends along the north