ice unleashes torrents of water over the earth’s sur-
face, causing sea levels to rise. As water pours over
the Bering land bridge (see entry for CA. 25,
TO 12,000 B.C.), the land route between Asia and
North America disappears. Some immigrants who
crossed over the bridge retreat back to Siberia be-
fore the process is complete. Others are trapped
in their new homeland. These people and their
descendants will gradually move south to more
hospitable environments and eventually populate
the entire North and South American continents.ca. 10,900 to 9000 B.C.Large wild game species
become extinct.
The mammoth, mastodon, giant sloth, and other
big game species begin to die out throughout
North America. Their extinction leads to the end
of the Clovis cultural tradition (see entry for CA.
9200 TO 8900 B.C.), in which early Indians relied
on hunting large game animals for their survival.
The reason these game species disappeared is un-
clear. One prominent theory holds that they were
overhunted, while another contends that chang-
ing climate conditions as the last ice age came to
an end, killed off the animals’ food supply, and
dried up their watering areas.ca. 9500 to 5000 B.C.The Paleo-Indian tradition emerges in
eastern and central North America.
The first people in North America develop the
Paleo-Indian tradition. The Paleo-Indians are
hunters of large wild mammals, such as mam-
moths, mastodons, and giant sloths. Within the
tradition emerges several cultures, including the
Clovis (see entry for CA. 9200 TO 8900 B.C.) and
Folsom (see entry for CA. 8500 TO 8000 B.C.) cul-
tures, which are characterized by innovations in
the crafting of projectile points—the stone tipson Paleo-Indian hunting tools. The Paleo-Indian
tradition will slowly fade as the climate of North
America grows warmer. The rising temperatures
will lead to the demise of many large game ani-
mals (see entry for CA. 10,900 TO 9000 B.C.) and
at the same time offer early Indians new species of
flora and fauna to use as food sources (see entry
for CA. 8000 TO 4000 B.C.).ca. 9200 to 8900 B.C.The Clovis culture emerges in central
North America.
Named after an excavation site near present-day
Clovis, New Mexico, the Clovis culture of early
Indian people develops throughout central North
America. These people are identified by three-to-
four-inch projectile points crafted from chipped
flint and fluted at the lower end. (These are now
known as Clovis points.) The fluting makes it
easy for Clovis hunters to create simple spears by
attaching points to wooden poles. Mammoths
are the preferred prey, but these roving hunters
also stalk caribou, bison, antelopes, and sloths.
The Clovis tradition disappears with the dying
out of the mammoths and other prehistoric big-
game species (see entry for CA. 10,900 TO 9000
B.C.).ca. 9000 B.C.Humans settle all of
North America.
Only several thousands of years after humans
began migrating from Asia over the Bering land
bridge (see entry for CA. 25,000 TO 12,000 B.C.),
their descendants are found in all regions of North
America, as they have learned to adapt to a wide
variety of environments. These Paleo-Indians live
in small, isolated bands of about 15 to 50 people.
They survive by gathering wild plant foods and
hunting game, using simple tools.ca. 10,900 to 9000 B.C.