The Redstone River is a large river in the Northwest Territories of Canada. It is about 289 kilometres (180 mi) long. It is a tributary of the Mackenzie River, joining it on the left bank some 100 kilometres (62 mi) north of Wrigley. Draining a rugged and high area of the Mackenzie Mountains, the Redstone watershed is sparsely populated; in fact, there are no significant settlements within the basin.