Troutline

Cowlitz River

Washington·Southwest Washington·46.50° N, 122.55° W
Flow
2,320 CFS
Cowlitz River below Mayfield Dam
Water Temp
—
Condition
Below Normal
Weather
55°F
Partly Sunny
near Mossyrock

Insights

Wind
Wind 1 mph — calm
Easy casting and clean surface presentations.
Flow
Low flows at 2,320 CFS
Fish are spooky. Lighten tippet and lengthen leaders.

It's only honest to start with what the Cowlitz is not: it is not a fly-fishing river the way the Yakima or the Deschutes are. It's Washington's largest hatchery steelhead and salmon factory, and the crowd that fishes it is overwhelmingly gear and bait. The action centers below the Barrier Dam at the Cowlitz Salmon Hatchery near Salkum, where fish stack up in staggering numbers and so do anglers — the 'combat' water below the barrier and the mile down to the Blue Creek launch is bobber-and-jig, plunked bait, and side-drifted eggs from before dawn. Show up expecting solitude and a dry-fly rise and you'll be disappointed.

What the river actually gives a fly angler is different, and it's worth knowing exactly where you fit. There are three real openings. First, the sea-run cutthroat program that peaks in September and October — thousands of hatchery cutthroat get released each year, run down to the Columbia estuary and back, and come home aggressive, chasing small streamers and soft hackles and even taking dries in low, clear late-summer water. Second, a modest but genuine summer-steelhead swing fishery in the riffles and runs above Blue Creek, best June into fall on a two-handed rod. Third, and most overlooked, the river itself: below the hatchery zone it runs fifty-plus miles of gravel bars and gliding runs down through Ethel, Toledo, and Castle Rock, and the gear crowd works maybe a mile below Blue Creek and a few hundred yards below the barrier, leaving the rest to whoever's willing to row it. Much of the bank is private, so a drift boat or raft is the practical way to reach the good water.

Flows are the wildcard. Releases from Mayfield Dam and the Tacoma Power system drive the river, and it fishes across a wide window — roughly 1,800 to 7,500 CFS at the Blue Creek reach is the commonly cited good range. It blows out and colors up after heavy Southwest Washington rain, and the dirtiest slug of all comes when the Toutle dumps its ashy glacial load into the lower river below Castle Rock, so after a storm the water fishes best above the Toutle. Well upstream, above Riffe Lake and Mayfield Lake, the Packwood-to-Randle reach is a separate, smaller resident-trout stream with a completely different character — glacially tinged flows off Mt. Rainier and wild rainbows, effectively a different river that happens to share a name.

Species

  • Coastal Cutthroat Trout
    Primary (fly target) · Aug-Oct (peak Sep-Oct) · 10-18"

    The best true fly opportunity on the river. Thousands of hatchery sea-run cutthroat are released each year from the Cowlitz Trout Hatchery; they run to the Columbia estuary and return aggressive, chasing small streamers, soft hackles, and Reverse/Knudsen Spiders, and taking dries in low, clear late-summer water. Lightest trout-spey or single-hand gear is plenty.

  • Steelhead (summer-run)
    Common · Jun-Oct · 6-10 lb

    The fly-friendly steelhead window. Swingable in the riffles and runs above Blue Creek on a dry line or light Skagit head. Fewer fish than the winter run, but this is when the swung fly makes sense. Counts accelerate June into July.

  • Steelhead (winter run)
    Common · Dec-Apr (peak Mar-early Apr) · 6-12 lb

    The river's overall headline draw, but mostly a gear season. Hatchery returns often run 3,000-5,000 fish. There's Skagit swing water in the lower river when conditions allow, for those willing to fish it in gray skies and horizontal rain.

  • Chinook Salmon (spring run)
    Common · May-Jul · 12-25 lb (to 30)

    The Cowlitz's trophy salmon, with big returns of 10,000-25,000 fish. A gear-and-bait fishery, not a fly-rod target.

  • Chinook Salmon (fall run)
    Common · Sep-Oct · 12-25 lb

    Fall kings in the lower river, overlapping the sea-run cutthroat season. A gear fishery.

  • Coho Salmon
    Common · Sep-Dec (peak early Nov) · 6-12 lb

    Very strong silver runs. Gear-dominated, but coho are occasionally taken on flies below the barrier and in the lower river when they're fresh and aggressive.

  • Chum Salmon
    Present · Nov-Dec · 8-15 lb

    Wild only and release-only; an incidental catch in the lower river in late fall.

  • Resident Rainbow Trout
    Present (upper river) · Jun-Oct · 8-14"

    The quarry on the upper Cowlitz between Packwood and Randle, above the reservoirs — wild resident rainbow trout in a small free-flowing mountain reach off Mt. Rainier. A completely different trip from the lower hatchery river; glacial melt can cloud it in summer.

Ideal wading flow1,800–7,500 CFS
Blow-out>9,000 CFS
Ideal water temp48–58°F

September-October is the biggest fly window: peak sea-run cutthroat, October caddis, and summer steelhead still around. June-July is next, as summer-steelhead counts accelerate and the river swings well. December-April is winter steelhead for those willing to Skagit-swing in the rain (mostly a gear season), and spring belongs to the Chinook gear crowd. Roughly 1,800-7,500 CFS at the Blue Creek / below-Mayfield reach is the commonly cited good range — cutthroat fish best toward the low end, steelhead swinging tolerates the high end. After heavy rain the Toutle dirties the lower river, so fish above the Toutle. Overcast favors steelhead and cutthroat surface activity; warm bluebird days drop and clear the water, good for sight-fishing cutthroat but tougher on the steelhead.

Sections

4 sections on this river

Upper Cowlitz: Packwood to Randle (above the reservoirs)

WadeSteelhead · Rainbow Trout

A separate, smaller free-flowing mountain reach above Riffe Lake and Mayfield Lake, following the US-12 corridor between Packwood and Randle — glacially tinged flows off Mt. Rainier and a wild resident rainbow trout fishery that has nothing to do with the anadromous hatchery river downstream. USGS gauges sit at both Packwood and Randle. Wadeable in reaches, though glacial melt can cloud it through summer. Anglers treat this as an entirely different river from the lower Cowlitz.

Best for: Wild resident rainbow trout on dries, nymphs, and terrestrials — a small-stream mountain trip, not the steelhead river. Best when summer glacial melt isn't clouding the water.

Barrier Dam to Blue Creek (the combat zone)

Wade & FloatSteelhead · Salmon · Cutthroat · Rainbow Trout

Big, pushy runs and holding water immediately below the Cowlitz Salmon Hatchery's barrier dam near Salkum — the highest fish concentration and the highest angler concentration on the river. Everything stacks here: winter and summer steelhead, spring and fall chinook salmon, coho salmon, and sea-run cutthroat trout. It's overwhelmingly a gear-and-bait fishery of bobber-and-jig and side-drifted eggs from before dawn, so fly anglers work the edges — swinging summer steelhead through the riffles above Blue Creek and targeting cutthroat around the hatchery outfalls.

Best for: Everything is here, but it's crowded and gear-dominated. Fly anglers swing summer steelhead in the upper riffles and pick off sea-run cutthroat trout near the hatchery outfalls.

Blue Creek to Toledo / Ethel

FloatSteelhead · Cutthroat · Rainbow Trout

Below the Blue Creek launch the crowds thin fast. This is long, gently sloping gravel-bar water — tailouts and gliding runs that are classic swing and float water once you're past the hatchery combat zone. The bank is mostly private, so it fishes as a drift-boat float. This is the under-pressured heart of the fly fishery: sea-run cutthroat trout on small streamers and dries in September and October, and summer steelhead on the swing where the two-handed rod earns its keep. Public access at Massey Bar and near Toledo.

Best for: Sea-run cutthroat trout on small streamers and soft hackles (Sep-Oct) and swung summer steelhead, away from the crowds. A boat is required for good access.

Toledo to Castle Rock (lower river)

FloatSalmon · Cutthroat · Rainbow Trout

The wide, slower valley river running down toward the Columbia confluence, with the USGS gauge at Castle Rock sitting at the bottom of the reach. This is the fifty-plus miles of lightly fished lower river — good sea-run cutthroat trout and fall coho salmon water where the river is fishable. It's the first stretch to color up after heavy rain, because the Toutle River dumps its ashy, glacial load in below Castle Rock; after a storm, fish above the Toutle.

Best for: Sea-run cutthroat trout and fall coho salmon on a drift-boat float, with the whole lower river essentially to yourself. Turbid after Toutle-driven storms.

Regulations

Current fishing rules and restrictions

Cowlitz regulations are set by WDFW and change frequently with run strength and by emergency rule, so always verify the current rules before fishing. As of January 1, 2026 a Columbia River Salmon and Steelhead Endorsement (CRSSE) is required to fish salmon or steelhead anywhere in the Columbia system and its Washington tributaries, including the Cowlitz. Barbless hooks are required for salmon and steelhead, wild (unclipped) steelhead must be released, and specific reaches around the barrier dam, Blue Creek, and the mouth open and close on run-specific schedules.

  • Columbia River Salmon and Steelhead Endorsement (CRSSE) required as of Jan 1, 2026 for salmon or steelhead, in addition to a Washington freshwater license and catch record card
  • Barbless hooks required for salmon and steelhead; night closure and anti-snagging rules apply seasonally around the hatchery zone
  • Wild (adipose-present) steelhead must be released; retainable hatchery fish carry a healed adipose-fin clip
  • Wild chum salmon are release-only
  • Hatchery steelhead daily limit: WDFW issued an emergency e-rule increasing the lower Cowlitz hatchery steelhead daily limit — check the current e-rule before you go
  • Cutthroat retention follows WDFW's Southwest Washington rules and is frequently selective-gear or release; confirm annually
  • Reaches (above the barrier dam vs. Blue Creek vs. the mouth) open and close on run-specific schedules — effectively year-round for one species or another

The CRSSE replaced/renamed the prior Columbia River endorsement as of January 1, 2026. The lower-Cowlitz hatchery-steelhead limit was raised by emergency rule (WDFW e-rule id 1477) — always check the current e-rule and the WDFW emergency-rule page before fishing, as Cowlitz rules are among the most run-sensitive in the state.

Source: Washington Department of Fish & Wildlife. Regulations change annually — verify before fishing.

Access & Logistics

Getting there, fly shops, and lodging

Getting There

Salkum, WA

~1.5-2 hrs from Seattle (I-5 to Exit 68, Toledo-Salkum); ~1 hr from Portland, OR to the lower river; ~45 min from Olympia

Fly Shops

Camping & Lodging

Ike Kinswa State Park on Mayfield Lake and Lewis & Clark State Park are the main campgrounds, plus Mayfield Lake Park; motels and RV parks cluster around Salkum, Toledo, and Castle Rock, with full services at Longview/Kelso near the mouth and at Packwood/Morton for the upper river.

This is a boat river below the hatcheries — much of the bank is private, and wade access is limited to the hatchery launches (Barrier Dam / Cowlitz Salmon Hatchery and the Blue Creek launch at the Cowlitz Trout Hatchery) and a handful of public bars like Massey Bar. Dedicated fly shops on the river are few; Lost Creek in Onalaska is the one local shop, and most fly guiding travels down from Seattle and Portland.

Conditions data is live from public monitoring networks. Regulations change annually — always verify current rules with your state fish & wildlife agency before fishing.

More in Washington

View all 15 rivers

Other regions

Hoh RiverWA

A glacial rainforest river off the west side of the Olympics and one of the last wild winter-steelhead fisheries in the Lower 48 — swung flies for fish that average 10-12 pounds when the water drops into its emerald-green window under ~2,500 CFS. It blows out fast and clears slow, coastal conservation rules keep you out of the boat and off the wild fish, and mid-season closures are common, so the Highway 101 gauge and the WDFW emergency-rule page decide every trip.

Icicle CreekWA

A cold, granite-bottomed Cascade freestone that pours out of the Alpine Lakes Wilderness and meets the Wenatchee River at Leavenworth. Scenery-first small-stream trout water — wild rainbows and westslope cutthroat in the 6-12" range on attractor dries once summer runoff drops, plus a heavily managed lower reach with a seasonal hatchery salmon story. Native-fish sensitive: bull trout and Upper Columbia steelhead are ESA-listed and can't be targeted.

Klickitat RiverWA

Washington's classic Columbia Gorge swing river — a glacier-fed tributary off Mount Adams that runs largely undammed to the Columbia at Lyle. The draw is the fall run of summer steelhead, taken on a dry line and a swung fly through the lower canyon runs. Spey water first; plan it around the calendar, not the hatch, and know that glacial turbidity, not flow, decides whether it fishes.

Little Spokane RiverWA

A slow, cold, spring-fed tributary that joins the Spokane River northwest of the city — wild hybridized redband trout in a weed-lined, almost meadow-stream setting minutes from downtown. Unusual water: the streambed is privately owned, so the real fishery is a non-motorized, no-anchor, no-bank-fishing catch-and-release float through the lower Natural Area. A quiet, technical, low-and-clear paddle-and-cast, not a wade river.

Methow RiverWA

North Central Washington's classic snowmelt freestone, tumbling out of the North Cascades near Mazama and running southeast through the Methow Valley past Winthrop, Twisp, and Carlton to the Columbia at Pateros. An attractor-and-hopper river for wild redband rainbows and trophy-class westslope cutthroat, with federally protected bull trout — the whole trout fishery is catch-and-release under selective-gear rules.

Naches RiverWA

The freestone alternative to the neighboring Yakima — a snowmelt river for wild redband rainbows and westslope cutthroat on the dry east slope of the Cascades. A ~10-mile catch-and-release, selective-gear stretch runs from the Tieton confluence up to Rattlesnake Creek, and the fishing quality climbs as you drive upstream toward the forks, away from the irrigation-tapped lower river.