I am only commenting regarding British Columbia and Western Canada.

Fur did not become a major commodity until after the arrival of Europeans. While the Europeans valued beaver pelts the most, the natives valued the silky smooth pelts of the ermine with preference towards the white hides and used beaver for bedding. Early European hatters preferred "Made Hides," a skin that had been used by the natives for bedding for a year before being offered for trade, over that of a fresh unused pelt so the traders paid premium prices for these hides. At times the premium could be as much as 10 times the value of fresh hide.

(As the Indians slept on their beaver hides the long coarse guard hairs would fall off leaving the soft jnner hair close to the skins. Early European hatters had to go through a difficult and time consuming process to remove the guard hairs from the beaver pelts, hence the reason for a greater value placed on made hides.)

In 1690 Henry Kelsey left Hudson's Bay and travelled to the Canadian prairies with hopes of convincing the Indians living there to trap and bring their hides to the Hudson's Bay Company's trading posts 900 miles to the east. In his journal Kelsey notes that the people he called Stone Poets, known to us as Assiniboine or Sioux, had all their needs and wants for living available in their homelands and were not inclined to make the trip for items they could readily find at home. The Northern tribes such as the Chipewyan and Cree lived in a much harsher environment so were easily convinced that they would benefit by making the long journey. In 1793 Duncan M'Gillivray, soon to be a partner in the Northwest Company, writes similar observations in his journal and recommended that an new organization and trading network to bring the trade goods to the Indians, thus cutting the HBC out of the market.

The early Pacific fur trade came into being almost by accident. Captain Cook was sent by the British Admiralty to search the Northern coasts with the hope of finding the Northwest Passage, a fabled sea route that crossed the North American continent. Cook did not find this passage. During this voyage cook needed water and timbers so anchored next to an Indian village in Nootka Sound, and named this place Friendly Cove because of the warm reception they received there. During this brief visit the sailors traded personal items such as mirrors, knives, combs etc and bits of metal and nails for salmon, food and otter skins. The otter skins were used for bedding and were tattered and abused when the sailors later stopped in Canton China. There they discovered that these ragged bits of furs commanded prices upwards of a year's pay each, so they returned to England wealthy men. Thus began the Pacific fur trade.

THIS ARTICLE gives a fairly decent look at pre-contact inter tribal trading.