between the coastal Tlingits and the interior First Nations developed, where the coastal peoples would trade eulachon oil and other coastal goods for native copper and furs found in the interior. The Yukon was part of the long disappeared Beringia and hosted a wide variety of megafaunal species like steppe wisents, American lions, short-faced bears, woolly mammoths, giant beavers, American mastodons, stag-moose, ground sloths, Camelops, dire wolves, caribou, muskoxen, saiga, American cheetahs, bison, grizzly bears, Equus scotti, Equus lambei, gray wolves, and yaks. First Nations Estimates of the population of the Yukon Territory at the beginning of the 19th century vary greatly. Some historians estimated that about 8,000 people lived in the territory. While other estimates were between 7,000 to 8,000 people. One estimate put the number at more than 9,000 people. Another estimate showed that by the year 1830, the number of indigenous people was about 4,700. The main part of the territory of the modern Yukon was occupied by various Athabaskan tribes. In the north, in basins of Peel River and Porcupine River there lived Kutchin or as they call themselves Gwitchin. About the middle of Yukon River, on the border with Alaska, there lived the Hän people. Northern Tutchone occupied most of the central part of the Yukon, in the basins of the Pelly River and the Stewart River. The Southern Tutchone were located in the south-west part of the Yukon. In the south-east, in the basin of Liard River, there lived the Kaska Natives. In the south, near the lakes in upper courses of Yukon River, there lived the Tagish. In the south-west, in the riverheads of the White River, there lived Upper Tanana. Besides Athabaskan, on the Arctic coast of modern Yukon, including Herschel Island, there lived the Inuit (Eskimo). And in the south, down the Teslin River, there lived continental Tlingit (Teslin) whose language together with Athabaskan languages is included into Na-Dene language family. Covered with snow, the area around Mount Saint Elias in the extreme south-west of the Yukon was unsettled. 19th century In the 18th century, Russian explorers began to trade with the First Nations people along the Alaskan coast, and later established trade networks extending into Yukon. European incursions into what later became the Yukon started in the first half of the 19th century with the fur trade. Hudson's Bay Company explorers and traders from Mackenzie River trading posts used two