Hay River (Canada) Hay River (Canada) The Hay River (in South Slavey: "Kátå’odehche") is a large river in northern Alberta and southern Northwest Territories, Canada. It originates in the muskeg of north western Alberta, flows west to British Columbia, then curves northward and returns to Alberta, where it follows a north-northeast course towards the Northwest Territories. After passing over two main waterfalls, the Alexandra Falls and Louise Falls, it flows through the town of Hay River and discharges into the Great Slave Lake. From there, its waters are carried to the Arctic Ocean by the Mackenzie River. Hay River has a total length
Mackenzie River . Six other lakes in the watershed cover more than , including the Williston Lake reservoir, the second-largest artificial lake in North America, on the Peace River. The river discharges more than of water each year, accounting for roughly 11% of the total river flow into the Arctic Ocean. The river is frozen for most of the year, with the ice typically breaking up by early to mid-May in the south, and late May-early June in the north. Ice breaks up earlier on the tributaries, sometimes causing ice jams and flooding where they meet the Mackenzie. In the middle of