Cutthroat are the native trout of the interior West. Before rainbows, browns and brookies were carried in by rail, nearly every cold river from the Rio Grande headwaters to the Columbia and from the Sierra to the Black Hills held some form of Oncorhynchus clarkii, and each isolated basin shaped its own. The species is really a collection of subspecies, most named for the drainage they evolved in, and the practical difference for an angler is that a cutthroat trip is usually a trip to a particular subspecies in its particular water. The orange or red slash under the jaw is the family mark. Spot pattern, body color and size tell you which one you are holding.
Yellowstone cutthroat
The fish of the Yellowstone drainage: heavy-bodied, bronze to gold, with large spots concentrated toward the tail. Native to Yellowstone Lake, the Lamar, and the Yellowstone River down through Montana. The Lamar River in the park is the purest place on this site to fish for them, a wild population restored through the park's management after the illegal introduction of lake trout collapsed the Yellowstone Lake population that feeds it. The Yellowstone through Paradise Valley lists Yellowstone-strain cutthroat averaging fourteen to eighteen inches, most active during the Salmonfly and caddis hatches, and notes that they hybridize with rainbows in some reaches. Yellowstone Lake itself is the center of the recovery effort, and fishing there is direct participation in it.
Bonneville cutthroat
The native trout of the ancient Lake Bonneville basin, which today means Utah, southeastern Idaho and a slice of Wyoming and Nevada. Paler than a Yellowstone fish, with sparser, larger spots. This site lists them on the Bear River, where they dominate the upper canyon and tributaries; the upper Logan; the Uinta River, where they are the dominant fish throughout; the Upper Provo tributaries; the Strawberry River tailwater; and the Blacksmith Fork, Duchesne, Lake Fork and East Fork Sevier. Bear Lake holds its own genetically distinct Bear Lake strain. Several of these waters count toward the Utah Cutthroat Slam, a program run by Utah's wildlife agency and Trout Unlimited that asks anglers to catch the state's four native cutthroat forms in their home drainages. The Utah trout hub lists the rest.
Westslope cutthroat
The cutthroat of the northern Rockies, native to the Columbia headwaters in Idaho, western Montana and Washington, and to the upper Missouri. Smaller-spotted than a Yellowstone fish, with the spots concentrated above the lateral line and toward the tail. This is the most widely fished cutthroat on the site because it dominates so many free-flowing Idaho rivers. The Lochsa, St. Joe and Salmon all list westslope cutthroat as the dominant resident trout, twelve to eighteen inches, eager for attractor dries all summer. In Montana they are in the upper Gallatin and its tributaries, Rock Creek, the Blackfoot, Bitterroot and Clark Fork. In Washington the Methow lists them as the everyday fish, and Flathead Lake holds a lake-run population that spawns in the Flathead system.
Snake River fine-spotted cutthroat
Found only in the upper Snake drainage of Wyoming and eastern Idaho, and immediately recognizable: hundreds of tiny spots spread evenly over the body, like pepper. It is the signature fish of three rivers here. The Snake through Jackson Hole lists them at fourteen to eighteen inches, aggressive on caddis and hoppers along the grass banks in August and September. The South Fork below Palisades is the most famous fine-spotted fishery in the world, with the same size class and one of the West's most intense Salmonfly hatches. The Teton valley section holds them in spring-creek water where they get selective on Pale Morning Duns. The New Fork carries a Wind River Range strain, and Jackson Lake has them cruising the shallows in early summer.
Lahontan cutthroat
The largest cutthroat, native to the Lahontan basin of Nevada and eastern California. It evolved in big, alkaline desert lakes and grows accordingly. Pyramid Lake, managed by the Pyramid Lake Paiute Tribe under its own permit rather than a state license, is the place to fish for them, from shore or a ladder in winter and spring with size 2 to 4 Woolly Buggers stripped slowly. The Truckee through Reno is the site of an active restoration returning Lahontans to the river for the first time in more than a century, and Walker Lake holds them seasonally. Both pages ask that any Lahontan you encounter be released immediately.
Colorado River and Rio Grande cutthroat
The Colorado River cutthroat is the native fish of the Green and upper Colorado drainages in Colorado, Wyoming and Utah, often the most vividly colored of all, with crimson flanks on spawning males. Displaced from most of its big-river range, it survives mainly in headwaters. On this site it is listed in the upper canyon of the Cache la Poudre, where the page calls it less common but highly valued for its conservation significance; the Colorado and Wyoming hubs cover the rest of the recorded range. Northern New Mexico has its own: the Rio Grande cutthroat, the southernmost of all, listed on the upper Pecos above Cowles and in the Red River headwaters. The Green River tailwater in Utah and the Provo above Jordanelle list cutthroat that have been stocked at various times. The North Umpqua lists native cutthroat in its headwaters above Toketee.
Fishing for a native fish
Cutthroat are the easiest trout to catch and the easiest to hurt. They rise to attractor dries readily, a Royal Wulff, Humpy, Stimulator or Chubby Chernobyl in 10 to 14 covers most summer days, and they take a fly slowly, so wait a beat before setting. Because they spawn in spring and hybridize with rainbows wherever the two overlap, which is why the cutbow exists, most native populations are managed as catch and release, with rules that vary by drainage. Check the state agency, or the park or tribe where they manage the water, before you go. Then keep the fish wet, keep it brief, and put it back where it has lived for ten thousand years.