Cutthroat Trout

Look under the jaw first. Cutthroat trout have a red, orange, or yellow slash mark on each side of the lower jaw, right where the gill plates meet. That mark is the whole ballgame for telling them apart from rainbow trout, which lack it entirely. Body color varies a lot by population, from olive-gold to silver, and all cutthroat carry black spots concentrated toward the tail, but the throat slash is the one mark that holds up everywhere.

Cutthroat and rainbow trout also interbreed where their ranges overlap, producing "cutbows" that show a faint or partial slash and a mix of both patterns. If the slash is weak or muddy rather than sharp, you are probably looking at a hybrid rather than a pure cutthroat. Cutthroat can also be confused with brown trout, but browns have larger, often halo-ringed spots and no throat slash, and their body shape tends to be heavier through the shoulders. Golden trout, a close relative found in some high mountain lakes, share the spotting pattern but run much brighter yellow-orange overall and still lack the true jaw slash in its bold red form.

Cold, clear rivers, high mountain lakes, and headwater streams across the Mountain West and the Pacific Northwest. Cutthroat need clean gravel, cold temperatures, and good oxygen, so they tend to live upstream of where other trout do, in the thin, fast water near the source.

Coastal cutthroat live differently. Along the Pacific coast, some populations run between rivers and saltwater, showing up in tidal creeks and estuaries as well as freshwater. Inland, cutthroat hold in pools and riffles, tucked behind boulders and logs, and stack up in the deeper bends of small streams.

Mostly insects: mayflies, caddis, stoneflies, and terrestrials like ants and grasshoppers that fall or get blown into the water. Cutthroat also eat small minnows, eggs from spawning fish, and the occasional crustacean. They feed at or near the surface often enough that dry flies and small surface lures work well.

Light spinning gear or a fly rod both work. Drift a small spinner, an inline spinner, or a nymph through pools and current seams, letting it swing naturally past likely cover. Cutthroat are not picky the way some trout are, but they spook easily in small clear streams, so approach quietly and cast from downstream when you can.

A dry fly like an Elk Hair Caddis or a Parachute Adams fished on a dead drift will draw strikes in summer, especially in the evening. In lakes, work the shoreline and inlet areas with a small spoon or a nymph under a strike indicator. Many cutthroat waters are catch-and-release only or have strict slot limits to protect native populations, so check your state's regulations before you fish.