Westslope Cutthroat Trout

Westslope Cutthroat Trout
Latin Name

Oncorhynchus clarkii lewisi

Group Name


Taxonomy details


Westslope Cutthroat Trout are found in a wide range of habitats but do best in cold, clean, moving water with various forms of cover such as undercut banks, pool-riffle habitat and riparian vegetation. The Westslope Cutthroat Trout has a disjunct distribution on both sides of the Rocky Mountains. In the United States, it occurs in drainages in Montana, Idaho, Washington, Oregon and Wyoming. In Canada, it is restricted to the upper Kootenay, upper Columbia and South Thompson drainages in British Columbia. The native Alberta population occurs in the Bow and Oldman drainages of the South Saskatchewan River. The Westslope Cutthroat Trout has also been widely introduced in many naturally fishless lakes and rivers.

Species Description

The Westslope Cutthroat Trout is a member of the Salmonidae family. It has a streamlined body shape with small, irregularly shaped dark spots. It has a series of small basibranchial teeth at the back of the throat. The Westslope Cutthroat Trout's colour ranges from silver to yellow green with red on the front and sides of the head. Spawning fish often develop a bright red colouration over the entire body. It is typically small in size at 150 to 230 mm (28 to 142 g); larger individuals rarely exceed 460 mm (1400 g).