Bonnet Plume | Tsaih Tl'ak Njik River

The remoteness of the Yukon’s Bonnet Plume River has contributed to preserving its pristine wilderness. The headwaters of the river are the Mackenzie Mountains, which straddle the drainage divide separating the Yukon and the Northwest Territories. The river flows over 350 kms before joining the Peel River, which flows northward across the Yukon/Northwest Territories border to the Mackenzie River delta.

Three mountain systems – the Mackenzies, Werneckes and Richardsons – converge in the Bonnet Plume drainage area. Extensive folding and faulting contributed to the area’s complex geologic history. During the earliest Laurentide glacial advance, ice covered all the valleys of the Bonnet Plume area. Extensive cirque development in the Wernecke Mountains indicates strong alpine glaciation, and other glacial landforms such as arêtes, moraines and rock glaciers are common. Continuing erosional forces create hoodoos along the middle sections of the river, and fluvial processes result in extensive river braiding. One of the most dramatic physiographic features of the area occurs just below Bonnet Plume Lake, where a large rockslide has transformed the valley, forcing the river to carve a canyon through the massive deposit of rock.

The Bonnet Plume region is noted for its wildlife habitat that supports large populations of sheep, caribou, moose and grizzly bear. The watershed is home to the Bonnet Plume caribou herd, one of the largest sedentary woodland caribou populations in the Yukon. The cottonwood/spruce forests and lichen woodland areas of the valley are also considered excellent moose habitat.

A sizable sheep population inhabits the Wernecke Mountains, and relatively high densities of grizzly have been reported in the river area. Bird species include peregrine and gyrfalcon, eagles, ruffed grouse, rock ptarmigan, loons, ducks and swans. The lower Bonnet Plume River is considered a sensitive and valuable fish habitat, and a spawning and nursery area for a number of fish species including Arctic grayling, slimy sculpin, round whitefish and Dolly Varden char.