Mackenzie River Passing Great Bear Lake, Canada66.1N 120.3W
The Mackenzie River carries brown sediments past the frozen Great Bear Lake (upper right) in Canada’s Northwest Territories, on its way towards the Beaufort Sea and Arctic Ocean. It is the longest river in Canada at 1,738 kilometres (1,080 mi).
Many other lakes dot the landscape near the river. Some are blue, having thawed during the warmer summer months, while many others are still frozen. The Mackenzie River itself generally freezes over in October and begins to thaw in May, meaning it is only navigable for approximately five months of the year.