What Is a Redband Trout? A Guide to the Native Rainbows of the Inland Northwest
Spend enough time fly fishing the Inland Northwest and eventually someone will hold up a particularly beautiful rainbow trout and ask:
“Is this a redband?”
It’s a simple question with a surprisingly interesting answer.
Redband trout are some of the most distinctive fish we encounter on our rivers. They can have brilliant red sides, olive or bronze backs, heavy spotting and the dark vertical parr marks we normally associate with juvenile trout. But a redband isn’t simply a particularly colorful rainbow.
The real difference is written in the fish’s ancestry. And once you understand that story, the rainbows swimming in rivers like the Spokane, Yakima, Kootenai and Clark Fork become considerably more interesting.
What Is a Redband Trout?
First things first: a redband is a rainbow trout.
Rainbow trout belong to the species Oncorhynchus mykiss. Redband trout belong to that same species. So redbands aren’t a separate species in the way a rainbow and a brown trout are. Instead, the name generally refers to native interior lineages of rainbow trout that evolved east of the Cascade and Sierra Nevada ranges.
The Columbia River redband—the fish most relevant to much of the Inland Northwest—is generally classified as:
Oncorhynchus mykiss gairdneri
The familiar coastal rainbow is generally classified as:
Oncorhynchus mykiss irideus
Both are rainbow trout. But they represent different evolutionary histories.
Interior redbands are themselves diverse. Scientific assessments recognize major redband groups associated with the Columbia, Klamath and upper Sacramento basins, and considerable genetic differentiation can exist even among populations within the same large river drainage.
That makes “redband” much more meaningful than simply the color of the fish. (USGS)
How Can You Identify a Redband Trout?
This is where things get tricky.
Redbands certainly can be spectacularly colorful. Depending on the individual and population, you might see:
a strong red or orange lateral band
an olive, bronze or yellowish body
relatively large black spots
dark vertical parr marks retained into adulthood
orange or reddish coloration around the gill plate
light edging on some fins
Those are useful clues. They aren’t proof.
A coastal-origin rainbow can develop a brilliant red stripe. A native redband can sometimes look surprisingly ordinary. Age, sex, spawning condition, habitat and individual variation all affect appearance.
More importantly, different rainbow-trout lineages can interbreed.
When introduced hatchery rainbows reproduce with native trout, genes from those introduced fish can become incorporated into the native population—a process called introgression.
That means a wild rainbow in an interior river might be predominantly native redband, a native fish with some introduced rainbow ancestry, a naturalized descendant of introduced rainbows, or some mixture of those histories.
You generally can’t determine which one you’re holding just by looking at it.
When biologists really need to answer that question, they use genetics. A rangewide scientific assessment found that although redbands were believed to occupy about 25,400 kilometers of stream habitat, only a relatively small portion of that range had actually been genetically tested. (USGS)
So on the river, appearance gives us clues. It doesn’t give us a genetic test.
What Makes Redband Trout Different?
The important distinction isn’t really what a redband looks like. It’s where it came from and how it evolved there.
Interior rainbow trout became separated from coastal populations and developed distinctive genetic lineages within the Columbia Basin and other western watersheds. Over time, individual populations adapted to their particular environments. Some of those environments are surprisingly harsh for trout.
Redbands occupy everything from cold mountain rivers to streams that become remarkably warm and variable during summer. Research comparing desert and montane redband populations has found physiological and genomic evidence of adaptation to those different thermal environments. (OUP Academic)
That doesn’t mean redbands are somehow immune to warm water. They’re still coldwater salmonids with thermal limits. It means that thousands of generations living in particular watersheds have produced populations adapted to the places they call home.
That’s part of what makes native redbands so valuable—particularly as western rivers face warming temperatures, drought, habitat fragmentation and changing streamflows.
Are Redband Trout Just Landlocked Steelhead?
This may be the question we hear most often on the Spokane River.
There’s a grain of truth behind it, but “landlocked steelhead” isn’t really an accurate description of a redband trout. Here’s why.
A steelhead isn’t a separate species from a rainbow trout either.
Steelhead are Oncorhynchus mykiss that express an anadromous life history: they are born in freshwater, migrate to the ocean and eventually return to freshwater to spawn. Rainbow trout remain in freshwater.
WDFW puts it very simply: steelhead and rainbow trout are the same species; the difference is their life history. (WDFW)
And those two life histories aren’t always genetically separate.
Where resident rainbow trout and steelhead occur together, they can interbreed. Research summarized by WDFW shows that their offspring can potentially express either strategy. Whether an individual becomes resident or anadromous reflects a combination of genetics, environmental conditions and the condition of the individual fish. (WDFW)
That means redband and steelhead aren’t opposite categories. “Redband” primarily tells us something about evolutionary ancestry. “Steelhead” tells us something about life history.
Historically, resident inland redbands and anadromous O. mykiss occurred within portions of the Columbia Basin at the same time. Idaho Fish and Game still recognizes redband populations in drainages such as the Salmon and Clearwater where steelhead also occur. For management purposes, Idaho currently uses “redband trout” for populations above barriers where the anadromous life history can no longer be maintained. (Idaho Fish and Game)
So are Spokane redbands landlocked steelhead?
Not in the simple sense that today’s Spokane redbands are steelhead that became trapped behind dams.
Genetic research by Washington Department of Fish & Wildlife examined rainbow trout from 20 tributaries and three mainstem locations throughout the greater Spokane River drainage. Populations in unstocked tributaries above barriers were genetically distinct from hatchery fish and appeared to represent native inland redband rainbow trout. Other populations showed evidence of hatchery introgression. (WDFW)
In other words, resident native redbands weren’t simply manufactured by twentieth-century dams.
The better way to think about it is that the native inland O. mykiss lineage has the biological capacity to produce different life histories. Where passage to the ocean was available, resident and anadromous forms could exist within the larger system. Where migration became impossible—whether because of natural or human-made barriers—the resident life history remained.
So when someone in the boat asks whether a Spokane redband is basically a landlocked steelhead, my answer would be:
“They’re very close relatives—actually the same species—but a redband isn’t simply a steelhead that got stuck behind a dam. Steelhead and resident redbands are different life-history expressions of O. mykiss, and native resident redbands were already part of the Inland Northwest’s fish fauna.”
That’s a subtle distinction. But it’s also a much more interesting story.
Rainbow Trout in the Spokane River
The Spokane has a genuine native inland redband heritage.
WDFW genetic research found substantial geographic structure among rainbow trout throughout the Spokane drainage. Populations from tributaries above barriers that hadn’t been stocked were genetically distinct from hatchery rainbow and steelhead stocks and appeared to represent native inland redband rainbow trout. (WDFW)
The same research also found evidence of hatchery introgression in some populations.
That’s not surprising. Hatchery rainbow trout have been introduced throughout the West for more than a century, including within the Spokane drainage.
What did you catch on the Spokane?
If we put a beautiful wild rainbow in the net on the Spokane River, redband is a reasonable and biologically meaningful description of the native fishery we’re pursuing.
But we shouldn’t claim that the appearance of an individual fish proves it is a genetically pure redband.
A better answer is:
You’re holding a wild rainbow from a river system with native inland redband ancestry. The amount of native versus introduced rainbow ancestry can vary within the drainage, and you can’t determine an individual fish’s genetic history from coloration alone.
That may be less tidy than simply saying “it’s a redband.” But it’s much closer to what the science actually tells us.
Rainbow Trout in the Yakima River
The Yakima tells another version of the same story.
Native O. mykiss in the Yakima belong to the interior Columbia Basin lineage, and historically the basin supported both resident rainbow trout and anadromous steelhead.
But the Yakima also received introductions of nonnative hatchery rainbow trout.
A peer-reviewed genetic study of upper Yakima rainbows found allele frequencies intermediate between native inland Columbia Basin populations and introduced hatchery populations—evidence that the fish represented genetic admixture between native and nonnative rainbow stocks.
Interestingly, the researchers concluded that domesticated resident hatchery rainbows, rather than hatchery steelhead, were probably responsible for much of that introgression. (OUP Academic)
What did you catch on the Yakima?
You’re catching a wild interior Columbia Basin rainbow trout from a population with native ancestry and a history of hatchery introgression.
That distinction between wild and genetically pure native is important.
A trout can be born in the Yakima, reproduce naturally and spend its entire life in the river—and therefore be completely wild—while still carrying some ancestry from trout stocked generations ago. So calling every Yakima rainbow a genetically pure Columbia redband goes farther than the evidence allows. Calling it part of a wild interior rainbow population with native Columbia Basin ancestry is much more defensible.
Rainbow Trout in the Kootenai River
Of the four rivers we guide, the Kootenai gives us perhaps the clearest redband story.
Columbia River redband trout are native to the Kootenai River drainage.
And they’re not one genetically uniform population.
A peer-reviewed study of Kootenai redbands found substantial genetic divergence between populations from different watersheds within the drainage—enough that the researchers recommended using watershed-specific fish if populations ever needed to be supplemented or reintroduced. (USGS Publications)
More recent research has revealed just how interconnected the Kootenai population can be.
A 2025 study used otolith chemistry—the chemical signature recorded in a fish’s ear stone as it grows—to investigate where Kootenai redbands originated. Of 329 fish examined, only about 18.5 percent originated from mainstem spawning. The remainder were assigned to 31 tributaries throughout the basin. Some were captured as far as 153 kilometers from their natal tributary. Researchers also found multiple life-history strategies, from fish remaining resident for several years to highly migratory individuals moving between tributaries and the main river. (USGS)
That means the redband we put in the net on the Kootenai may be connected to a tributary many miles away.
What did you catch on the Kootenai?
Here we can answer more confidently:
You’re fishing native Columbia River redband country.
Introduced trout and genetic introgression still complicate portions of the broader drainage, so appearance alone can’t establish the ancestry of an individual fish. But the native rainbow trout of the Kootenai is the Columbia River redband, Oncorhynchus mykiss gairdneri. For me, knowing that makes catching one in the big river even more interesting.
Rainbow Trout in the Clark Fork River
The Clark Fork provides the most useful contrast of the four rivers.
Rainbow trout are not native to the Clark Fork drainage.
Idaho Fish and Game’s current fisheries management plan specifically excludes the Clark Fork and Coeur d’Alene drainages from the native distribution of Columbia River redband trout. (Idaho Fish and Game) Montana Fish, Wildlife & Parks likewise identifies the rainbows of the middle Clark Fork as nonnative.
But they’ve certainly become successful. Montana FWP reports that rainbow trout and rainbow × westslope cutthroat hybrids generally make up about 70–80 percent of the trout population in the middle Clark Fork. The agency manages this as a wild trout fishery emphasizing natural reproduction. (Montana FWP)
That creates a useful distinction. The Clark Fork’s rainbows can be completely wild without being native. They were born in the river. They reproduce naturally. They’ve established self-sustaining populations. But their ancestors were introduced by people.
Meanwhile, the native trout story of the Clark Fork belongs primarily to species including the westslope cutthroat trout and bull trout.
Rainbow trout also hybridize with westslope cutthroat in the drainage, producing the fish anglers commonly call cutbows. Montana FWP reports that these hybrids constitute a significant part of the middle Clark Fork trout population. (Montana FWP)
What did you catch on the Clark Fork?
If it’s a rainbow:
You’re holding a wild, naturalized rainbow trout—not a native Columbia River redband.
And if the fish displays characteristics of both rainbow and westslope cutthroat trout, there’s another possibility: you may be holding a rainbow × westslope cutthroat hybrid.
It’s one of the clearest examples of why wild and native don’t mean the same thing.
So, Is That Rainbow a Redband?
If you want the boat-side version, here’s how I’d answer it:
Spokane River: Probably best thought of as a wild rainbow from a native inland redband population, recognizing that hatchery introgression has occurred within the drainage.
Yakima River: A wild interior Columbia Basin rainbow with native ancestry, but from a population with a documented history of hatchery-rainbow introgression.
Kootenai River: Native Columbia River redband country. These are the native O. mykiss of the drainage, although individual genetic ancestry still can’t be determined by appearance alone.
Clark Fork River: A wild, naturalized rainbow—not a native redband. Rainbow × westslope cutthroat hybrids are also common.
And if someone asks whether a Spokane redband is a landlocked steelhead?
Same species. Closely connected evolutionary story. But no—the best evidence doesn’t support simply describing today’s Spokane redbands as steelhead that got trapped behind dams.
Why Does Any of This Matter?
You could reasonably ask whether any of this makes a difference when you’re standing beside a river with a trout in your net. I think it does.
Knowing what a fish is—and how it came to occupy that river—changes the way we see it.
A native redband isn’t simply a rainbow with especially beautiful coloration. It’s part of an evolutionary lineage shaped by a particular landscape: its geology, tributaries, temperatures, barriers, floods and droughts. Some populations became isolated. Others remained connected across enormous river systems. Some developed different migratory strategies. Some now live alongside descendants of fish humans introduced from hundreds or thousands of miles away. And some have survived a century of dams, hatchery introductions, habitat changes and warming water while retaining pieces of a genetic history that stretches back far beyond any of us.
The trout in your net is therefore more than a species name. It’s part of the history of the river.
And at Teeming Streams, understanding that history is part of understanding—and appreciating—the water we fish.
Sources and Further Reading
For this article, we’ve relied primarily on state and federal fisheries agencies and peer-reviewed fisheries research rather than general angling sources.
Small, M.P., McLellan, J.G., Loxterman, J., Von Bargen, J., Frye, A. & Bowman, C.Fine-scale population structure of rainbow trout (Oncorhynchus mykiss) in the Spokane River drainage in relation to hatchery stocking and barriers. Washington Department of Fish & Wildlife / Transactions of the American Fisheries Society. Documents genetic structure, hatchery introgression and apparently native inland redband populations within the Spokane drainage. (WDFW)
Campton, D.E. & Johnston, J.M. (1985).Electrophoretic Evidence for a Genetic Admixture of Native and Nonnative Rainbow Trout in the Yakima River, Washington.Transactions of the American Fisheries Society, 114(6), 782–793. Documents genetic evidence of native and introduced rainbow-trout admixture in the upper Yakima. (OUP Academic)
Knudsen, K.L., Muhlfeld, C.C., Sage, G.K. & Leary, R.F. (2002).Genetic Structure of Columbia River Redband Trout Populations in the Kootenai River Drainage, Montana, Revealed by Microsatellite and Allozyme Loci.Transactions of the American Fisheries Society, 131, 1093–1105. Documents substantial genetic structure among native Kootenai redband populations. (USGS Publications)
Ghere, C.L., Willmes, M., Hardy, R.S., Ross, T.J., Dunnigan, J., Wilson, S., Carleton, S. & Quist, M.C. (2025).Population Structure and Movement Dynamics of Redband Trout in the Kootenai River Basin.River Research and Applications. Documents tributary origins, diverse life histories and movements of up to 153 km among Kootenai redbands. (USGS)
Muhlfeld, C.C., Albeke, S.E., Gunckel, S.L., Writer, B.J., Shepard, B.B. & May, B.E. (2015).Status and Conservation of Interior Redband Trout in the Western United States.North American Journal of Fisheries Management, 35, 31–53. Comprehensive rangewide assessment of interior redband distribution, genetics and conservation. (USGS Publications)
Washington Department of Fish & Wildlife.Steelhead (Oncorhynchus mykiss) and supporting steelhead science documents. WDFW identifies steelhead and rainbow trout as the same species and summarizes research showing that resident and anadromous forms can interbreed and produce offspring capable of expressing either life history. (WDFW)
Idaho Department of Fish & Game.Fisheries Management Plan 2025–2030. Describes Columbia redband distribution, their relationship with steelhead and the absence of native redbands from the Clark Fork and Coeur d’Alene drainages. (Idaho Fish and Game)
Montana Fish, Wildlife & Parks.Statewide Fisheries Management Plan: Middle Clark Fork River Drainage. Identifies Clark Fork rainbow trout as nonnative and documents the prevalence of naturally reproducing rainbow trout and rainbow × westslope cutthroat hybrids. (Montana FWP)
Chen, Z., et al. (2018).Physiological and genomic signatures of evolutionary thermal adaptation in redband trout from extreme climates.Evolutionary Applications. Provides evidence of adaptive physiological and genomic divergence between desert and montane redband populations. (Wiley Online Library)
