A male Coho salmon displays one of the key differences to distinguishing it from it's seasonally overlapping steelhead: a hooked nose. Not pictured: forked tail featuring spots on both lobes of tail. | Photo: Freshwaters Illustrated - David Herasimtschuk
October 2025
Welcome back to the Deschutes Diaries! In this series, we delve into the dynamics of the Deschutes River, examining its past, present, and future challenges. In this issue, we explore fascinating and little known story of Deschutes River Coho salmon.
Through these articles, we’ll take a closer look at the events that shaped the Deschutes River we know today, and highlight Native Fish Society's efforts to protect and revive its wild abundance.
This is an ongoing series to showcase and open the conversation of our Deschutes: Return to Wild & Cool campaign. Along the way, we’ll be sharing important milestones, ongoing efforts, and how you can be a part of this vital work. Additional parts and updates will be posted over the next several months. Stay tuned!
This October, deep in the Deschutes canyon, I caught my fishing partner marching back upstream, a triumphant grin on his face.
“Did ya’ find one!?” I asked, anticipating he had found one of the prized A-run summer steelhead of the lower Deschutes River.
“Ha! Oh, did I! Take a look at this thing!” he exclaimed, whipping out his phone to show me a still-in-the-water photo of a beautiful chrome fish.
“Oh, I bet that DID put up a fight!” I say, laughing.
“What?!? That’s a great fish!” my buddy defends.
“It is a great fish! But you’re still on the hunt for a steelhead, my friend, because THAT, is a Coho,” I tell him, watching the perplexed look appear on his face.
“COHO!? I didn’t even know there were Coho in here!? Since when?” he exclaimed.
Let’s take a closer look!
Before large-scale hatchery introductions, coho salmon were native to coastal rivers of Oregon, including the Lower Columbia River tributaries and coastal drainages (like the Siuslaw, Alsea, and Umpqua). However, they did not naturally occur in the Deschutes River basin, which flows east of the Cascade Range into the Columbia River.
ODFW and NOAA documents indicate that Coho were historically present only in the lower Deschutes River and some Columbia River tributaries downstream, but not to the mid- or upper-basin (above where the Pelton-Round Butte dam complex).
Fisheries surveys and historical accounts list Chinook and Steelhead as the dominant anadromous salmonids in the Deschutes; Coho are not noted.
Coho are now present in parts of the Deschutes, but these are considered to be primarily hatchery-introduced stocks.
The Deschutes River flows from the eastern slope of the Cascade Mountains down to the Columbia River. Historically, it was too dry and too far inland for coho, which are more of a coastal species that prefer lower-gradient, wetter river systems with abundant off-channel rearing habitat.
It’s worth noting that Coho are considered native to Columbia River tributaries far upriver - like the Lostine in NE Oregon or the upper Clearwater in Idaho, and that Coho will travel quite a distance for suitable habitat, it’s just that a number of the mid-Columbia tribes - notably the Deschutes - held little to none of those habitat conditions.
So, before European settlement and dam construction, no records or traditional ecological knowledge indicate native Coho in the Deschutes. Instead, the river supported large populations of:
Spring and fall Chinook salmon
Sockeye salmon (in the Metolius system)
Summer steelhead
Now, reports from ODFW showed that more than 2,400 adult Coho salmon returned above Sherars Falls in 2024.
How did that happen? More to come on THAT in Pt. II.
General Appearance (Adult Coho in Freshwater)
| Feature | Coho Salmon (Oncorhynchus kisutch) | Notes |
|---|---|---|
| Size | Medium-sized: 8–12 lbs, ~24 inches average (can reach 20+ lbs) | Smaller than most Chinook, larger than sockeye or pinks |
| Body Color (Freshwater) | Males: reddish flanks, darker backs, hooked jaw (kype) Females: paler red to pink sides, olive back | Bright silver at sea; turn red as they approach spawning |
| Back and Tail Spots | Small black spots on upper lobe of tail (caudal fin) only | Chinook have spots on both lobes of the tail |
| Gum Line (Inside Lower Jaw) | White or light gray gums | Chinook have black gums — the key difference |
| Mouth Color (Interior) | Grayish with white gums | “White gum line = coho” |
| Anal Fin | Shorter base (12–17 rays) and squared shape | Chinook have longer anal fin (13–19 rays) |
| Dorsal Fin | Often with white leading edge | Helpful but subtle |
| Tail Shape | Slightly forked or square, few or no spots on lower half | Good quick field cue |
If you only have seconds to look:
Check tail spots → Only upper lobe = coho
Check gum line → White gums = coho
Check size → Mid-sized salmon (smaller than Chinook, larger than sockeye)
Check shape in freshwater → Red flanks + hooked jaw (male) = likely coho
Stay tuned in December as we dive deeper into “Then & Now” in Pt. II
Sources:
Deschutes Diaries is an ongoing series. Stay tuned for next month's topic!
If you have any questions or topics you'd love to see covered in Deschutes Diaries, please don’t hesitate to reach out – we’d love to hear from you! Send us an email with your questions and suggestions at info@nativefishsociety.org
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