* grant Shishmaref an easement across the Bering Land Bridge
National Preserve to reach a gravel source at Ear Mountain needed to control erosion;
They don't believe these ancient people traveled across the Pacific Ocean so the only possible route is across the Bering land bridge
. Unfortunately, researchers have not yet found any Australian DNA in any genetic samples from either North or Central America.
This was about the same time that the first people started moving into America via the so-called Bering Land Bridge
-- then an expanse of dry land between Alaska and Siberia which was submerged at the end of the last Ice Age, some 18,000 years ago, when glaciers melted and sea levels rose.
Whether they are migratory routes like the Bering Land Bridge
and Serengeti Trail or superb engineering feats like the Inca and Roman Roads, or Trans-Siberian Railway, each is a testament to the tenacity, inventiveness and determination of the human spirit.
Elias National Park and Preserve, Kenai Fjords National Park, and Katmai National Park and Preserve along the Gulf of Alaska, and Bering Land Bridge
National Preserve and Cape Krusenstem National Monument by the shore of the more northern Chukchi Sea--to remove marine debris from their most sullied beaches.
Scientists have long thought that humans passed from what is now Siberia to present-day Alaska via the Bering land bridge
, but recent studies are deepening the mystery around how some of the first people actually made it south into America.
Those land routes would have been somewhat similar to other ocean crossings, such as the Bering land bridge
humans traversed around 23,000 years ago between Asia and North America (,SN: 8/22/15, p.
Scientists have long thought the first settlers in North America arrived at the continent through an ancient land bridge connecting Siberia to Alaska. These people, after their arduous trek across the Bering land bridge
- a region that is now the Bering Strait - had to wait for the massive glaciers that covered the land, now known as Canada, to recede in order to move south and populate the continent.
"If there ever was an ice-free corridor during the Last Glacial Maximum," James Dixon of the University of New Mexico wrote in a recent study, "it was not in the interior regions of northern North America, but along the Northwest Coast." A "biologically viable" passage stretched along that coast from the Bering Land Bridge
to regions south of the glaciers starting about 16,000 years ago, he reported in the journal Quaternary International.
Archaeological and DNA evidence suggests that humans first crossed the Bering Land Bridge
from Siberia to Alaska about 15,000 to 20,000 years go.
In Alaska, meanwhile, melting sea ice and thawing permafrost have allowed winter storms to erode the coastlines of Cape Krusenstem National Monument and the Bering Land Bridge
National Preserve in Kotzebue Sound at an unprecedented rate.