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 different routes to enter Yukon and created trading posts along the way. The northern route started in Fort McPherson, Northwest Territories along the Mackenzie River, crossed the mountains into the Bell and Porcupine Rivers to the Yukon River. The southern route started at Fort Liard, Northwest Territories, then westward along the Liard River to Frances Lake and then along the Pelly River to its juncture with Yukon River.