Horn River formed along the middle course of the Horn River, and is followed downstream by the "Second Lake". The river turns south-west, where the "Mink Lake" is formed along its course. The Laferte River also flows into the Mink Lake. Horn River then flows south, and it receives the waters of the Bluefish River before it empties into the Mackenzie River, downstream from the Great Slave Lake), immediately upstream from Mills Lake, at an elevation of . The arch made by the river defines the "Horn Plateau", a flat elevated area that rises up to ) to the north and east,
Boats of the Mackenzie River watershed Landing north of Edmonton to the Slave River rapids, the only significant obstacle en route to the Mackenzie. In 1886, the S.S. "Wrigley" was launched on the other side of these rapids, at Fort Smith, and for the first time a steam-driven vessel operated on the Mackenzie River as far as Aklavik in the river delta before it spilled into the Arctic Ocean. A series of small portage trails were established between Smith's Landing (later Fort Fitzgerald) and Fort Smith to skirt the 16-mile rapids - this was later upgraded into a full road in the 1920s. In 1898 the