Try Your Own Idaho Native Trout Road Trip
By Daniel Ritz
Thankfully, many of Idaho’s more than 100,000 miles of rivers—891 miles of which are designated as wild and scenic—are flanked by major travel corridors, enabling an unparalleled travel experience for curious anglers.
In addition to the abundant, well-known and world-class fisheries like Henry’s Fork of the Snake River and Silver Creek, the lesser-discussed fact is that many of these easily accessible aquatic corridors are home to one or more of the five native species of trout found in Idaho, second only in native trout species diversity to Alaska and California.
Why Are Native Trout Species in Idaho Important?
In addition to their unique ecological value, the pursuit of Idaho’s native trout species offers anglers much more than the temporary satisfaction of a tug on the end of the line. Engaging with native species in a responsible manner enables anglers to step beyond simply tossing a fly (or lure) in the water and seeing what happens. Pursuing native species elevates fishing to an experience.
Whether you’re a lifelong angler looking to complete the Idaho leg of your Western Native Trout Challenge or a first-timer interested in gaining a better understanding of Idaho, a road trip to experience its native species is a sure-fire and fun way to appease your curiosity.
If you’re interested in creating and completing your own “Idaho Native Trout Slam,” here’s one route based on seasonal fishing trends that I’d suggest.
What Is Idaho’s State Fish?
The cutthroat trout (Oncorhynchus clarkii) is the official state fish of Idaho, home to three distinct subspecies. The name “cutthroat” refers to the iconic red coloration on the underside of the trout’s lower jaw.
Road Trip Stops
Fishing in Southwest Idaho
(Oncorhynchus mykiss gairdneri)
Often mistaken for rainbow trout, redband trout are actually a subspecies of the rainbow trout that exist in two well-defined geographic regions. The Columbia River redband trout is found in Montana, Washington and Idaho, and the Great Basin redband trout can be found in southeastern Oregon, Idaho and parts of California and Nevada.
Redbands are aggressive feeders, eager to take dry flies carefully placed in the pocket waters they inhabit. Be careful, though—their small stature leaves them wary of predators. Cautious approaches and presentations are often necessary.
How to Identify Redband Trout
The redband trout is similar in appearance to the rainbow trout but has larger, more rounded spots and parr marks that remain into adulthood.
Where & When to Fish Redband Trout
Redband trout can be found in the rivers and streams tributary to the Snake River from the Idaho–Oregon border upstream to Shoshone Falls.
March through June offers the greatest opportunity to fish for native redbands in southwest Idaho. Rain and cooler temperatures allow for responsible angling and a wider distribution of fish in the various rivers.
Suggested Gear & Flies for Redband Trout
- 3-weight fly rod
- General dry flies, #14 Parachute Adams
Fishing in Northern Idaho
(Oncorhynchus clarkii lewisi)
Traveling north, anglers will climb from the high desert of the more populous southwest into the pine-riddled national forests and wilderness of northern Idaho, including the Clearwater River drainage and the native waters of the westslope cutthroat trout.
Although commonly associated with the state of Montana, the historic range of westslope cutthroat trout is the most geographically widespread among the 14 subspecies of inland cutthroat trout. In Idaho, westslope cutthroat trout are native to streams and lakes in the upper Columbia River basin. Westslopes currently occupy about 59% of the nearly 56,500 miles of their historic habitat.
How to Identify Westslope Cutthroat Trout
While it can sometimes be difficult to distinguish the westslope from other cutthroat species, anglers can keep in mind that they generally have more small spots by the tail and none by the pectoral fins. The westslope cutthroat trout often has more of a silver or green hue than the Yellowstone cutthroat trout they share geographic proximity with. The average size of these fish is six to 16 inches.
Where & When to Fish Westslope Cutthroat Trout
Abundant westslope cutthroat trout populations can still be found in several northern Idaho rivers, including a number of world-famous creeks above Dworshak Dam in the North Fork of the Clearwater River drainage.
While all cutthroat trout are known to be migratory depending on spawning and other variables, the generally higher altitude range of this subspecies means July through August is ideal for fishing.
Suggested Gear & Flies for Westslope Cutthroat Trout
- 9-foot 5-weight fly fishing rod
- General dry flies, #14 Elk Hair Caddis
Fishing in Eastern Idaho
(Oncorhynchus clarkii bouvieri)
The historical range of the Yellowstone cutthroat trout in Idaho was upstream of Shoshone Falls on the Snake River and tributaries. It also existed across the Continental Divide in Yellowstone Lake, the Yellowstone River and its tributaries downstream to the Tongue. This makes Yellowstone cutthroat trout a fantastic way to share in the beauty of the Blue Ribbon streams of eastern Idaho.
Yellowstones are notorious for their eagerness to take dry flies off the surface. There’s not much better than seeing the vibrant cheeks of a Yellowstone rise out of iconic rivers such as the South Fork of the Snake River or the Teton River with the Continental Divide as a backdrop.
How to Identify Yellowstone Cutthroat Trout
Yellowstone cutthroats can be distinguished from other cutthroat trout by their larger black spots clustered toward the tail and by their gray, gold and copper hues. A mature Yellowstone cutthroat usually measures from six to 20 inches long.
Where & When to Fish Yellowstone Cutthroat Trout
The rivers draining the Continental Divide mountains of southwest Montana and northwest Wyoming into the Upper Snake River offer a variety of options to fish for Yellowstone cutthroat trout.
Tributaries to the Upper Snake River offer a long season, sometimes beginning as early as May with blizzard stonefly hatches followed by world-renowned terrestrial pattern fishing through September.
Suggested Gear & Flies for Yellowstone Cutthroat Trout
- 9-foot 5-weight fly fishing rod
- Dry flies, terrestrials, #8 and #10 Stimulators and grasshopper imitations
Fishing in Southeast Idaho
(Oncorhynchus clarkii utah)
While Bonnevilles inhabit the smallest geographic range of any of the native trout of Idaho, their recovery in far southeast Idaho is an incredible example of collaboration and compromise.
Once thought to be extinct, after an aggressive, coordinated recovery effort by multiagency conservation teams and private citizens, there are now at least 202 Bonneville cutthroat trout populations that occupy about 2,728 miles of stream habitat in 21 watersheds in Utah, Idaho, Nevada and Wyoming. A number of small streams, many of which are enveloped by the Cache National Forest, await anglers looking to catch this oft-forgotten native trout species in Idaho.
Some populations within the Bear River drainage near the intersection of Idaho, Wyoming and Utah continue to exhibit the species’ impressive life history and habitat requirement diversity, migrating seasonally between lower-elevation river systems and the cold, clear waters of high-elevation tributaries.
How to Identify Bonneville Cutthroat Trout
Bonnevilles can be identified by their spots—usually larger than other cutthroats and sparser as compared to rainbow.
Where & When to Fish Bonneville Cutthroat Trout
Bonneville cutthroat trout occupy most of the available tributary habitat in the Bear River Watershed.
Like their other cutthroat subspecies cousins, July through September is generally the ideal season for pursuing Bonneville cutthroat trout.
Suggested Gear & Flies for Bonneville Cutthroat Trout
- 7.5–8-foot 4-weight fly fishing rod
- General dry flies, #16 Sparkle Dun
Fishing in Central Idaho
Thanks to largely interconnected waterways, Idaho’s bull trout are dispersed across much of the state, from the Canadian border all the way south to drainages such as the Boise River.
They’re most common in cold-water rivers, which in summer often means upper-elevation streams. Bull trout need water 60° F or cooler, and water around 54° F is the ideal habitat for them.
When bull trout were listed as threatened under the federal Endangered Species Act in 1998, the U.S. Fish and Wildlife Service determined that Idaho Fish and Game regulations provided sufficient conservation benefits. In Idaho, that meant bull trout fishing was allowed, but harvesting was not. Those regulations are still in place, so bull trout can be caught, but they must be immediately released unharmed.
How to Identify Bull Trout
In Idaho, bull trout are often misidentified as brook trout, which are a non-native species in Idaho. Bull trout, lake trout and brook trout are all chars: members of the trout family with light spots on a dark background. The bull trout lacks black spots on the dorsal fin that the brook trout has. That’s the best way to tell these two species apart. The lake trout can also be easily distinguished from bull trout by its deeply forked tail.
Where & When to Fish Bull Trout
Bull trout can be a challenge to pursue due to their life history diversity and being highly migratory. Depending on a fish’s particular life history, bull trout can be found in small streams, large rivers, lakes and reservoirs. While this species may be elusive, anglers willing to put in the time to familiarize themselves with their movement patterns will find themselves in some of the most beautiful spots in the state, including the Frank Church–River of No Return Wilderness, the mighty Salmon River and the South Fork of the Boise River.
Suggested Gear & Flies for Bull Trout
- 9–10-foot 7-weight fly fishing rod
- Streamers, Dolly Llama
Fishing for Steelhead
(Oncorhynchus mykiss gairdneri)
Genetically, Idaho steelhead are rainbow trout (its subspecies being redband) that travel up rivers more than 700 miles from sea to spawn. Historically, steelhead occurred east of the Cascade Range in the Columbia River basin upstream of Kootenay Falls on the Kootenai River. These fish also occurred up to Albeni Falls on the Clark Fork–Pend Oreille drainage and downstream of Shoshone Falls on the Snake River.
How to Identify Steelhead
Steelhead can be identified by their heavy spotting above and along the lateral line. In males, the lower jaw can be hooked—a characteristic known as a “kype.” An adipose fin (the fin on the back between the tail and dorsal fin) is also present in native steelhead. This fin is clipped in hatchery fish populations.
Where & When to Fish Steelhead
Because steelhead are in so many places in the state over such a long period of time, it’s difficult to say where the “best place” to go steelhead fishing is. If an angler has a chance to follow the run upstream, the best time could be any month from July or August through May.
Anglers pursue hatchery steelhead beginning in August for the next nine months as they migrate up the Snake (downstream of Hells Canyon Dam), Clearwater (downstream of Dworshak Dam) and Salmon rivers.
Steelhead Guidelines in Idaho
Currently in Idaho, all wild (adipose fin intact) steelhead are catch and release only.
Suggested Gear & Flies for Steelhead
- 12–13-foot 8-weight two-handed Spey rod
- Wet flies, #5 Green Butt Skunk
Steelhead, Redband or Rainbow Trout?
While the redband trout native to Idaho are part of the rainbow trout (Oncorhynchus mykiss) species, not all rainbow trout are redband trout. Native Idaho steelhead are seafaring forms of the redband trout of the Columbia Basin.
Before You Hit the Road
The decision to pursue the native trout species of Idaho on a road trip can provide beginners and lifelong anglers alike with a life-changing crash course in natural history and conservation successes that you and your family are certain never to forget.
While little is guaranteed in fishing, I’m willing to assure you that a road trip to experience each of the native species of Idaho will leave you wondering not only what’s around the river bend but what’s in it.
We’ll see you out there.