Cutthroat Trout: Subspecies, Identification and Where to Fish

The cutthroat trout is the native trout of the American West, named for the red-orange slash under each side of its lower jaw. It comes in more than a dozen forms, from small headwater fish to the 41 lb Lahontan that still holds the record. Several of those forms are protected or already extinct. On a lot of the best cutthroat water, the fish you catch goes back.

Feel behind the tongue. A cutthroat has tiny teeth at the back of it, a rainbow does not, and that settles a faded slash when the fish is in your hand.

How do you tell a cutthroat from a rainbow or a cutbow?

The slash is the first mark: a streak of red to orange in the fold under each side of the lower jaw. The second mark is less famous and more reliable. A cutthroat has small basibranchial teeth on the floor of the mouth, behind the tongue, and its upper jaw extends past the rear edge of the eye.

The spots vary more than the slash. The Snake River fine-spotted form is named for its small spots, and the Paiute has almost none on its body.

The trouble is the rainbow. Cutthroat and rainbow trout hybridize freely where rainbows have been stocked, and the offspring, the cutbow, is fertile. Cutbows usually keep a red or orange slash, but fainter than a pure cutthroat would show. Where Yellowstone cutthroat live, a white leading edge on the anal or dorsal fin also points to rainbow blood. By looks alone a cutbow is hard to call, so treat a field ID as a best guess.

Where do you fish for cutthroat?

Cutthroat live in cold water from Alaska to New Mexico, and each form fishes differently. Coastal cutthroat include sea-run fish that feed in the salt around Puget Sound, the Washington coast and the lower Columbia. Washington runs a hatchery sea-run fishery on the Cowlitz River.

Westslope and Yellowstone cutthroat are the classic dry-fly fish of Montana, Idaho and Wyoming rivers. The Lahontan is a lake fish at heart and grows large where it has forage fish to eat; Pyramid Lake is the place.

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Which cutthroat lives where, and which are protected?

Federal status is the U.S. Fish and Wildlife Service’s; “not warranted” means the Service reviewed the fish for listing and declined. The second column is the species each form belongs to since the 2023 split.

Two stories sit behind that table. The first is Yellowstone Lake, home of the largest Yellowstone cutthroat population left. Lake trout were found there in 1994. The Park Service has since netted more than 5.1 million lake trout out of the lake, about 289,900 in 2025 alone, and says the netting has cut the lake trout spawning population by 87 percent since 2012. In one overnight set, 21 lake trout held the remains of at least 47 cutthroats.

The second is Colorado. A 2007 study had shown that several populations stocked as greenbacks were really Colorado River cutthroats. Then a 2012 study of museum specimens up to 150 years old found that the true greenback cutthroat survived in only one small creek, Bear Creek.

Can you keep a cutthroat?

The rules follow the status. In Yellowstone National Park every native fish, cutthroat included, must be released unharmed, and hooks must be barbless. Every lake trout caught in Yellowstone Lake must be killed. Colorado requires greenbacks to go back immediately.

Lahontan cutthroat, although threatened, may be kept where the state allows it under a special federal rule, and many Nevada waters are open. Check the state regulations for the water before you keep one; on a lot of the best cutthroat water the answer is catch-and-release.

Are they good to eat? Where it is legal to keep one, a cutthroat is a trout on the plate like any other. The catch is that many of the waters that hold pure fish either forbid keeping them or set slot limits that protect the big spawners.

How do you catch cutthroat?

Among anglers, cutthroat have a reputation as the most willing trout in the West, rising to a dry fly in water where browns and rainbows sulk.

The tackle is ordinary trout tackle. On streams, use a 4 or 5 weight fly rod, or an ultralight spinning rod with 4 lb line; for lake fish, heavier gear and sinking lines. The trout fishing guide covers the season and the rigs.

Because so much cutthroat water is catch-and-release, the handling matters: wet hands, a short fight and no time out of the water. The catch-and-release guide sets it out step by step. In late summer, keep an eye on the water temperature too.

How big do cutthroat get?

Most stream cutthroat are small fish. Lahontans run 8 to 22 in (20–56 cm) in larger rivers and lakes, and the lake forms are the only ones that grow truly big.

The all-tackle world record is a Lahontan of 41 lb (18.6 kg), caught by John Skimmerhorn at Pyramid Lake, Nevada, on Dec. 1, 1925. Nothing else is known about the catch. Outdoor Life’s roundup of the records names Adam Garcia’s 35 in, 19 lb (8.6 kg) Pyramid Lake fish of Nov. 5, 2016, taken on a woolly bugger, as the biggest cutthroat on fly tackle.

The cutbow has its own record: 34 lb 11 oz (15.7 kg), 41.13 in long, from American Falls Reservoir, Idaho, on July 25, 2011.

One cutthroat or four?

The name came from the outdoor writer Charles Hallock, who used it in The American Angler in 1884. The species question is newer. In November 2023 the joint names committee of the American Fisheries Society and the American Society of Ichthyologists and Herpetologists split the cutthroat into four species with no named subspecies. That committee sets the official common and scientific names of North American fishes.

1. Coastal cutthroat, Oncorhynchus clarkii: the Pacific coast, the only one that goes to sea.
2. Westslope cutthroat, O. lewisi: the northern Rockies.
3. Lahontan cutthroat, O. henshawi: the Great Basin of Nevada, California and Oregon.
4. Rocky Mountain cutthroat, O. virginalis: Yellowstone, Bonneville, Colorado River, Rio Grande, greenback and their kin.

Not everyone agrees. A 2026 paper in Evolutionary Applications, built on full mitochondrial genomes, argues that the four new “species” hide differences as deep as those between them. It keeps one species, O. clarkii, with eleven subspecies-level lineages.

The Endangered Species Act still lists the protected fish under their old subspecies names, and most state regulations still say “cutthroat”. For the angler, the names that matter are the regional ones in the table; they are what the rulebook and the stocking reports use. The trout hub sets the cutthroat beside every other American trout, including the golden trout, the other native trout of the high Sierra.

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