Referred to as “mariners and mountaineers,” steelhead often climb more than 6,000 vertical feet and travel more than 900 miles during their life-long roundtrips from Idaho’s rivers to the ocean and back again.
Connecting with an Idaho steelhead, notoriously powerful, uniquely designed for the wildest terrain in the Lower 48 and unfortunately increasingly difficult to catch, is the experience of a lifetime for many anglers.
What Is A Steelhead?
First things first: A steelhead is a native rainbow trout that migrates to the ocean as a juvenile and returns to fresh water as an adult to spawn. Unlike Pacific salmon, which always die after spawning, steelhead can rejuvenate so they may return to the oceans to start the anadromous cycle over. Otherwise, steelhead and rainbow trout are genetically identical. A rainbow trout is called a resident when they do not leave the stream to go to the ocean and spend their entire life in the stream. A steelhead is the name for a rainbow trout expressing anadromous or seafaring life history.
Stick with us: There are two subspecies of steelhead, the Redband steelhead trout (Oncorynchus mykiss gairdneri) which all are categorized as summer-run fish and enter the Columbia River from May through September. The other subspecies is called the Coastal steelhead rainbow trout (Oncorhyncus mykiss irideus) which can be summer, fall and winter run fish. If you remember one thing, remember that in the Columbia River basin, Coastal Steelhead trout are largely found west of the Cascade Range and all steelhead returning to Idaho are Redband steelhead trout (Oncorynchus mykiss gairdneri) and therefore are all considered summer-run fish
In Idaho, these steelhead are often classified into two groups, A-run and B-run, based on their size and ocean life history.
“Idaho’s A-run steelhead are usually found in the Snake and Salmon rivers,” Idaho Fish and Game explains “They (A-run fish) return from the ocean earlier in the year (usually June through August) and they most often return after spending one year in the ocean. Because of their early return and short stay in the ocean they usually weigh four to six pounds and are generally 23 to 26 inches in length.”
B-run steelhead, exclusively found in Idaho are revered by anglers around the world. Most often, B-run steelhead return to the Clearwater River and some tributaries of the Salmon River. These fish usually – but not always – spend two years in the ocean and start their migration to Idaho later in the summer or fall of the year (usually late August or September). After packing on the pounds an extra year and waiting an extra summer of growing in the ocean, B-run steelhead can return as significantly larger fish.
Steelhead can grow even larger when they spend a third year in the ocean before they return to Idaho to spawn. These steelhead are usually larger than 37 inches and often weigh more than 20 pounds.
When Are Steelhead in Idaho?
Steelhead can be found in the rivers of Idaho for the majority of the year and the sweet spot for fishing really depends on which river, time of year and method of fishing you prefer.
Fall Fishing: July-December
On the Snake River, fishing is best in September and October. The Clearwater River seasons open then, mostly for catch and release fishing, so be sure to check the regulations. As the run builds, fishing will get better and better all the way through to December when colder water is likely to slow down catch rates. The Salmon River, further upstream, doesn’t really get going until well into October in the lower and mid-reaches.
Spring Fishing: January to May
January and February can be great times to fish with a little more solitude. The days are shorter and colder and there are fewer anglers but the fish are out there. Things start to pick up again in late February and early March as ice dams begin to break up and allow the fish to continue their upstream migrations. The Salmon River, the Little Salmon River and the South Fork of the Clearwater generally provide the best fishing during the spring months before rivers are closed for steelhead fishing to allow the wild fish to spawn.
Fishing For Steelhead (Hint: You’ve Got Options)
Steelhead respond to a variety of angling techniques such as plunking, bobber and jig, fly fishing, side planer and spey casting with flies. Since steelhead are not feeding as they wait to spawn, it’s generally accepted that flies, lures and bait are agitating the fish enough to trigger a strike. While much is unknown about steelhead feeding habits, they are generally considered aggressive. As a general rule, the cooler the water temperatures the less active steelhead are therefore the less likely they are to move greater distances to take your fly/lure/bait.
Idaho fisheries are a mixed bag for anglers in the fall but are world renowned for fly fishing with spey (two-handed fly fishing rods generally over 13 feet in length used to cast artificial flies long distances.)
Alternatively, spring fisheries, with cooler water temperatures, generally lower water levels and clearer conditions are generally better suited for fishing a fly, lure or bait under a bobber.
As always, be sure to check Idaho Fish and Game regulations on tackle regulations specific to different rivers at different times of the year.
A Species in Decline
While Idaho’s fisheries largely depend on hatchery fish production to support a sportfishing season; the future of Idaho steelhead in no uncertain terms depends on recovering wild fish populations. Wild steelhead carry the biological adaptations and genetic diversity that allow these icons to return each year to their high mountain natal streams, survive surging spring run-offs, multiple fresh-to-salt water transformations and manage the 466-mile migration back to Idaho to spawn the next generation.
Historically, more than 40% of the salmon and 55% of the steelhead in the entire Columbia River system originated in the Snake River drainage. Before Idaho steelhead populations crashed in the late 1970s, records show more than 110,000 wild origin steelhead would return to the Snake River basin above what is now Lower Granite Dam.
Identifying Wild vs. Hatchery Steelhead
Special fish deserve special treatment, and it is important before you head out fishing to be able to clearly identify and differentiate between a wild and a hatchery steelhead.
Hatchery steelhead or salmon may be kept – within regulation limits – if the adipose fin (fin on the back of the fish between the dorsal and the tail) has been clipped as evidenced by a healed scar. Anyone fishing for anadromous (ocean-run) salmon and/or steelhead, except those expressly exempt, must have a valid fishing license as well as a salmon and/or steelhead permit(s) on their person. For more details on being a licensed angler – resident or out-of-state and for much more information on seasons, bag limits and much, much more, please be sure to visit Idaho Fish and Game website.
Daniel Ritz is a recovering journalist turned outdoor writer. Currently, he is the Communications and Outreach Coordinator of the Idaho Wildlife Federation, the founder of Jacks Experience Trading Company and the Conservation Field Editor for Swing The Fly. He lives in Idaho with his partner Holly, a giant cat named Julio and a small bird-dog named Trout.
Published on August 29, 2023
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