| Mountain River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Territory |
| Subdivision Name2: | Northwest Territories |
| Source1: | Mackenzie Mountains |
| Source1 Location: | Northwest Territories, close to watershed border with Yukon |
| Source1 Coordinates: | 64.0814°N -130.7872°W |
| Source1 Elevation: | 1738m (5,702feet) |
| Mouth: | Mackenzie River |
| Mouth Location: | between Norman Wells and Fort Good Hope, Northwest Territories |
| Mouth Coordinates: | 65.6833°N -128.8353°W |
| Mouth Elevation: | 70m (230feet) |
The Mountain River is a tributary of the Mackenzie River in Canada's Northwest Territories. Its source is in the Mackenzie Mountains close to the watershed border with Yukon. It flows eastward, joining the Mackenzie River just south of the Arctic Circle. The river flows about 370km (230miles), dropping over 1200m (3,900feet) over its course, with large volume rapids, fast current, and six canyons. The upper half of the river is surrounded by mountains which reach heights of over 2700m (8,900feet), with rock colours of buff, grey, cinnamon, green, and maroon. Wildlife includes caribou, moose, wolf, Dall sheep, grizzly bear, and black bear. It is considered an excellent but difficult wilderness canoeing river.