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Lake Merwin Fishing Report

Updated Fri, Oct 23, 2026 from live gauge and weather data

Lake Merwin on the North Fork Lewis: WDFW says kokanee are the main target, with tiger muskie, planted in 1995, also popular.

4/5
Good. Solid day ahead.Stable-to-falling pressure and workable wind line things up.
Lake level
228.00 ft
Air / High
48 / 62 F
Wind
WSW 3 mph

Sources: USGS gauge 14219950, Open-Meteo, solunar calculated for these coordinates.

Satellite view
Friday
23
October 2026

Today's Fishing Report

Generated this morning from live readings: gauge, weather model, sun and moon. A fresh report is published here every morning.

4/5Good. Solid day ahead.Stable-to-falling pressure and workable wind line things up.

Lake Merwin rewards those who follow the bait as the water cools. The gauge reads 228.00 ft, easing 2.00 over the week. Today brings clear skies, wind WSW around 3 mph, falling pressure near 1024 hPa and a high of 62. Water sits around 55 F for the season (estimated). With the waxing gibbous, the solunar majors run 9:48 AM-11:48 AM and 10:19 PM-12:19 AM: the windows to build the day around.

The plan, species by species

MuskellungeExcellent

This band covers the spring spawn, which in Wisconsin runs at 49-60Β°F; spawning muskies eat little and rarely chase lures, Wisconsin DNR says. After the spawn, and again as fall water cools, work large lures along weed edges and structure.

Northern pikeExcellent

The best band for pike: right after ice-out they move into flooded vegetated shallows to spawn, and they feed actively again as the water cools in fall.

Rainbow troutExcellent

This band overlaps Vermont's 54-66Β°F stream preference: fish feed across riffles, runs and pocket water, and in lakes WDFW says spring and fall bring them near the surface.

Landlocked salmonExcellent

Spring after ice-out and the fall cool-down are the surface seasons, with fish near shore and at stream mouths feeding on smelt: troll or cast streamers and smelt imitations.

Chinook salmonFair

Runs enter the rivers: drift roe or sand shrimp through travel lanes, plunk a wrapped plug, or float eggs in eddies and tidewater.

Tomorrow: Warmer at 68 F. The solunar majors shift about 50 minutes later.Next report: Sat, Oct 24, 6:30 AMHow this report is made β†’

Before you go

Washington requires a fishing licence from age 16, from $39.95 for residents. What a Washington licence costs and where to buy it β†’

Chasing muskellunge here? Check the size and bag limits with WDFW before you keep anything. The season dates for Washington, read off the agency, are on the Washington seasons page.

Water and weather

Live readings from Lake Merwin near Chelatchie.

Water level, last 30 days

USGS gauge 14219950.

228.35229.00229.65228.00 ft09/2310/0310/1310/23

Right now

Latest readings

Air temp48 F
High / Low62 / 45 F
WindWSW 3-5 mph
Pressure1023.9 hPa, falling
Sky / Rain3% cloud, 1%
Sunrise / Sunset07:37 / 18:09
MoonWaxing Gibbous, 91%
Water temp (seasonal)~55 F est.

Bite planner

Hour-by-hour bite forecast for today. Tap a bar to see why.

5 AM8 AM11 AM2 PM5 PM8 PMsunrisesunsetPRIMEPRIME

Which day to fish Lake Merwin this week

Today is the pick of the week on Lake Merwin, at 4 out of 5.

Best day this week: today, Oct 23 β€” good at 4/5, falling pressure, usually the best window of a week.

Today, Oct 23 β€” Good

Stable-to-falling pressure and workable wind line things up.

Solunar majors
9:48 AM-11:48 AM and 10:19 PM-12:19 AM
Minor period
4:14 AM-5:14 AM
Sun
07:37 to 18:09
Moon
Waxing Gibbous, 91% lit
Sky and wind
Overcast, 8 mph
Rain chance
1%

Forecast-based scores, less reliable further out: how the score is built.

Species guide

The species that matter on Lake Merwin: seasons, structure and how to fish each one. Today's ratings live in the report above.

Muskellunge illustration

Muskellunge

Fished from late spring into late fall where seasons allow

Muskellunge are solitary, fish-eating ambush predators of the pike family, holding in weed beds and other cover in lakes and rivers of the Great Lakes, upper Mississippi and Ohio basins. This band covers the spring spawn, which in Wisconsin runs at 49-60Β°F; spawning muskies eat little and rarely chase lures, Wisconsin DNR says. After the spawn, and again as fall water cools, work large lures along weed edges and structure.

Northern pike illustration

Northern pike

Best: cool water, from ice-out through spring, in fall and under the ice

A long, duck-billed predator of weedy lakes, slow rivers and backwaters that ambushes fish from vegetation. Wisconsin DNR points out that, unlike most of the state's common game fish, pike do their best feeding in cool water. The best band for pike: right after ice-out they move into flooded vegetated shallows to spawn, and they feed actively again as the water cools in fall.

Rainbow trout illustration

Rainbow trout

Spring and fall in most lakes; rivers fish year-round while the water stays cool

A cold-water trout native to Pacific drainages from Alaska to Baja California, now stocked in most states and fished in rivers, tailwaters and lakes. This band overlaps Vermont's 54-66Β°F stream preference: fish feed across riffles, runs and pocket water, and in lakes WDFW says spring and fall bring them near the surface.

Chinook salmon illustration

Chinook salmon

Seasons follow the runs: spring, summer and fall runs on the West Coast, and late summer into fall in Great Lakes rivers

The largest Pacific salmon, caught by trolling and mooching at sea and by drifting and plunking in rivers as adults return to spawn; also stocked in the Great Lakes. Runs enter the rivers: drift roe or sand shrimp through travel lanes, plunk a wrapped plug, or float eggs in eddies and tidewater.

Landlocked salmon illustration

Landlocked salmon

Spring and fall near the surface, deep in summer, and under the ice in winter

Landlocked salmon are Atlantic salmon that complete their whole life in fresh water, feeding mainly on rainbow smelt in cold lakes of Maine and the Northeast. Spring after ice-out and the fall cool-down are the surface seasons, with fish near shore and at stream mouths feeding on smelt: troll or cast streamers and smelt imitations.

When to come: the Lake Merwin calendar

Activity by species and month, and how the water warms through the year. Tap any cell.

Species activity by month

1 = slow, 5 = peak. Current month highlighted.

J
F
M
A
M
J
J
A
S
O
N
D
Muskellunge
Northern pike
Rainbow trout
Chinook salmon
Landlocked salmon
SlowPeak

Water temperature through the year

Typical surface temperature for this water type; today is around 55 F (estimated, not a reading).

304050607080JanMarMayJulSepNovOct, ~55 F now

Angler reports

Real reports from real anglers, reviewed before publishing. The water log below tracks each day automatically.

No angler reports yet this weekBe the first: your report helps every angler who checks Lake Merwin today, and we feature the best catch of the week.

Water log, last days

Auto-logged from live data
Thu, Oct 22

4/5 Good. Solid day ahead. Stable-to-falling pressure and workable wind line things up. Muskellunge led the card at excellent. High of 66 F, wind to 11 mph.

Wed, Oct 21

3/5 Fair. Fish the windows. A steady pattern: dawn and dusk carry the day. Muskellunge led the card at excellent. High of 77 F, wind to 6 mph.

Tue, Oct 20

3/5 Fair. Fish the windows. A steady pattern: dawn and dusk carry the day. Muskellunge led the card at excellent. High of 75 F, wind to 10 mph.

Where roughly, what depth, what bait. Skip anything you want to keep secret.
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Before you go

License

Washington requires a valid fishing license for adults. Buy online from the state agency; one-day options exist for visitors.

Regulations

Washington fishing license. Merwin Lake (reservoir): game fish open year-round under statewide limits; salmon under landlocked salmon rules (WDFW, updated Oct 5, 2026). Statewide: tiger muskie 50 in. minimum, 1 a day; kokanee 10 a day, no minimum. Release all bull trout and Dolly Varden. Two-pole fishing allowed.

Access

PacifiCorp boat launches at Speelyai Bay and Cresap Bay (fee on weekends). Very limited shore access. Reservoir levels: PacifiCorp, 800-547-1501.

About this water

Lake Merwin (Merwin Reservoir), a North Fork Lewis River impoundment in Clark and Cowlitz counties, Washington: 3,835.6 acres at 242 feet elevation (WDFW), formed in 1931.

Fishing Lake Merwin: the full guide

Kokanee and tiger muskie

WDFW describes Merwin Reservoir as a North Fork Lewis River impoundment near Ariel, on the south side of State Route 503, shared by Clark and Cowlitz counties. It formed after Merwin Dam was completed in 1931 by the Inland Power and Light Company. WDFW says kokanee are the main target, and tiger muskie, first planted in 1995, are also popular. Its species list for the lake is bull trout, Chinook and coho salmon, kokanee, northern pikeminnow, tiger muskie and rainbow trout.

Rules on Merwin

Washington's rules for Merwin Lake (reservoir) keep game fish open all year under statewide size and daily limits, with salmon under landlocked salmon rules. Statewide, tiger muskie must be at least 50 inches and only 1 may be kept a day. Kokanee have no minimum size and a daily limit of 10; when fishing with bait, every legal kokanee caught counts toward the limit whether kept or released. WDFW notes that all bull trout and Dolly Varden must be released, and two-pole fishing is allowed.

Launching and water levels

PacifiCorp operates the boat launches at Speelyai Bay and Cresap Bay and charges a fee to launch on weekends. WDFW warns that the reservoir level fluctuates with runoff, which can make boat access difficult at times, and that shore access is very limited. PacifiCorp gives updated reservoir levels at 800-547-1501.

Common questions

How big can a legal tiger muskie be?

To keep one it must be at least 50 inches, and the limit is 1 a day under Washington's statewide rule. Most anglers release them.

What else can I catch in Lake Merwin?

WDFW says kokanee are the main target. Its species list also includes rainbow trout, Chinook and coho salmon, northern pikeminnow and bull trout, which must be released.

Can I fish Merwin from shore?

Only in a few places: WDFW calls shore access very limited. Most anglers launch at PacifiCorp's Speelyai Bay or Cresap Bay ramps.

Is fishing good at Lake Merwin right now?

Check the daily report at the top of this page: it is regenerated every morning from live data. Today's read: Good. Solid day ahead. Stable-to-falling pressure and workable wind line things up.

Nearby waters

Kalama River16 miLewis River18 miCowlitz River38 miSandy River38 miRiffe Lake38 miDrano Lake43 mi

Where this page's numbers come from

River and reservoir readings
USGS 14219950 β€” Lake Merwin near Chelatchie
Read from the USGS Water Data API (api.waterdata.usgs.gov). Latest value timestamped 2026-10-23 at 15:00 UTC.
Weather and pressure
Open-Meteo forecast model
Queried at 45.9795, -122.4484 in this water's own timezone. A model, not an observation.
Moon and solunar windows
Calculated on this site
Astronomical calculation from these coordinates and the date, not a third-party feed. How much weight it deserves.
Pages checked
The facts in the written guide were checked against these pages, from the agencies and operators that manage the water, on October 6, 2026. Anything we could not verify was taken out.
The written guide on this page
Pablo Ruiz Quintero
How this page was made. The daily report is computed by our scoring engine from live readings; nobody types it. The written text was drafted with AI assistance from the official pages listed above, and its facts were checked against those pages by automated verification on October 6, 2026; anything that could not be verified was taken out. Pablo Ruiz Quintero sets every guideline, the data-verification system and the minimum standards a page must meet to be published, reviews page structure and approves what goes live; the responsibility is his, and the AI carries out the work. We work this way because it is how one person can keep every page current with named sources. Errors are published in the verification log; the full policy is in the editorial policy.

Readings refresh on a 30-minute window. The full method, with every figure and its source, is on how our reports are made. Something wrong here? Tell us and it goes in the log with the date.