How did Alexander Mackenzie’s trip down the Mackenzie River aid Arctic exploration?

Alexander Mackenzie’s 1789 expedition down the Mackenzie River significantly aided Arctic exploration by establishing a second known point on the Arctic Ocean coast.1

By successfully navigating from Lake Athabasca to the river’s delta, Mackenzie helped open the interior of Arctic lands to further study and commerce. Following his journey, the North West Company established a series of trading posts along the river, extending as far north as Fort Good Hope. The existence of these established outposts proved vital for later Arctic exploration, as they provided the necessary infrastructure and logistical support that made subsequent overland expeditions—including those led by John Franklin and his successors—possible.213