Westslope Cutthroat Trout
Westslope cutthroat trout are native to a narrow slice of Canada — the Bow and Oldman drainages in southern Alberta, and the upper Kootenay, upper Columbia, and South Thompson drainages in British Columbia.
They're a bucket-list fish for western Canadian fly anglers: wild, stream-born, and increasingly rare. Both the Alberta and BC populations carry protected status, which shapes how and where you can fish for them.
Also known as WCT, cutthroat, cutty
- Olive to yellow-green back, greenish-gold sides, with the defining red-orange slash marks under each jaw — the feature that names the whole cutthroat group.
- Spots are small, irregular, and concentrated toward the tail and on the dorsal, adipose, and caudal fins; few spots near the pectoral fin — a key difference from other cutthroat subspecies.
- More silvery overall than most cutthroats; spawning fish flush bright red across the body.
- Typical stream fish run 6–16 inches; individuals over 18 inches are uncommon, with fish rarely exceeding about 18 inches (1,400 g) even in quality habitat.
What to know
Habitat Distribution
- Native to Canada on both sides of the Rockies: the Bow and Oldman River drainages (South Saskatchewan system) in Alberta, and the upper Kootenay, upper Columbia, and South Thompson drainages in BC.
- Cold, clear, moving water is the core habitat — pool-riffle streams with undercut banks, riparian cover, and clean gravel. Also found in naturally fishless mountain lakes where they've been introduced for recovery purposes.
- Alberta populations now occupy only a fraction of their historical range; genetically pure fish are largely confined to headwater streams above natural barriers that keep non-native trout out.
- The BC population (Pacific Designatable Unit) is listed as Special Concern; the Alberta population (Saskatchewan-Nelson Rivers DU) is listed as Threatened under Canada's Species at Risk Act.
Key Locations
- Bow River drainage, southern Alberta — headwater tributaries hold some of the last genetically pure Alberta populations; access is limited and regulations are strict.
- Oldman River drainage, southern Alberta — similar headwater stream habitat; recovery stocking efforts are ongoing in select mountain lakes including Rawson Lake and Picklejar Lakes.
- Upper Kootenay drainage, southeastern BC — the Wigwam River is a documented stronghold for genetically pure BC westslopes.
- Upper Columbia and South Thompson drainages, BC — native range in Canada's Pacific DU; cold, clear tributaries in the Columbia Mountains.
Specific Spots
- Undercut banks and overhanging riparian vegetation give westslopes shade and overhead cover — prime lies in summer when water warms.
- Pool tails and the seam where fast water meets a slow eddy are classic feeding stations; fish hold in the slower water and dart into the current to intercept food.
- Riffle heads and pocket water behind boulders concentrate drifting insects and are worth working carefully, especially during a hatch.
- In mountain lakes, fish cruise the littoral zone near inlet streams, particularly during spring and fall when temperatures are cooler.
Westslope Cutthroat Trout FAQ
Answers from onWater's species guide.
What are the best lures and bait for Westslope Cutthroat Trout?
Small inline spinners (size 0–1) in gold or silver are reliable in pocket water and pools, the flash and vibration trigger strikes even when fish aren't actively surface feeding.
What flies work for Westslope Cutthroat Trout?
Dry flies are the go-to: an Elk Hair Caddis (imitates adult caddisflies), Parachute Adams (general mayfly imitation), and a Purple Haze (attractor pattern) cover most situations, westslopes rise willingly and reward a clean drift.
When is the best time to fish for Westslope Cutthroat Trout?
Late spring through early summer: post-runoff, once streams clear and drop, is prime time, fish are active and hatches begin in earnest. Summer (July–August): early morning and evening fishing is most productive as midday temperatures push fish into shade; terrestrial patterns shine in August.
How do you catch Westslope Cutthroat Trout?
Most anglers wade small mountain streams, working upstream and presenting dry flies or small nymphs to individual fish holding in pools, riffles, and pocket water. Boat access is rarely relevant given the stream sizes involved.
What do Westslope Cutthroat Trout eat?
Aquatic insects, mayflies, caddisflies, and stoneflies, make up the bulk of the diet in stream environments. Westslopes are notably surface-oriented and will rise readily to dry flies; matching the hatch with an Elk Hair Caddis (imitates adult caddisflies) or a Parachute Adams (general mayfly imitation) covers most...
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