Coastal Rain River · Granite · British Columbia, CA

Harrison River

Chehalis Flats, Harrison Mills, B.C

The Harrison is the Lower Mainland's trophy sea-run cutthroat river — a short, big, lake-fed Fraser tributary where cutthroat and bull trout (Dolly Varden) follow enormous autumn salmon runs and gorge on fry and eggs.

Today · A proper day on the water
Pheasant Tail Nymph
Forecast · Today
A proper day on the water
A proper day for it. Work the seams with an upstream nymph, switch to the dry when they show.
75% projected
Today's fly
Pheasant Tail Nymph
Pheasant Tail Nymph
Conditions on the water · Today
Estimate
Level
Dry recently
No gauge reading
Water temp14.5°C
ClarityClear
Weather16°C
WindN 4 km/h
Pressure1015 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Cutthroat Trout
Ideal
15°C est.ideal 9–15°C
0°14°28°
How to fish it · for Cutthroat Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Good — water clarity is right today, though insect activity could be better.
Likely species
Mayflies
Caddisflies
Hatch timeline · todayPeak at 11am

12pm(now) — Reed Smut

Stage: On emergersApproach: Emerger or dryActivity: 86%
Also:Trico40%Flying Ants26%
Peak emergence window7 food groups active

Peak activity at 11am — Reed Smut (Reed Smut, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 as a supporter.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
Brown DunHatch
2
3
3
3
3
3
3
2
Western Green DrakeHatch
2
2
Flav (Small Western Green Drake)Hatch
2
3
2
Mahogany DunHatch
2
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Cutthroat Trout fly box
Permits & access
Permit required — see local rules.
  • Dolly Varden protected/C&R; salmon DFO-regulated
  • Verify current BC regs (Region 2) and DFO notices.
What's coming
Plan ahead
5-day outlook
Other water nearby · 3
Chehalis River
8.0 km
Steelhead · Cutthroat trout · Coho salmon
Vedder / Chilliwack River
16 km
Steelhead · Rainbow trout · Coho salmon
Skagit River (BC)
60 km
Rainbow trout · Bull trout
Gallery · 2
  1. Chehalis Flats, Harrison Mills, B.C
  2. Terrain map of the venue
    Terrain map
About this water

The Harrison is the Lower Mainland's trophy sea-run cutthroat river — a short, big, lake-fed Fraser tributary where cutthroat and bull trout (Dolly Varden) follow enormous autumn salmon runs and gorge on fry and eggs. Lake-buffered and clearer than the flashy coastal rivers, it offers superb fall fly fishing for big cutthroat on fry and egg patterns, with salmon and steelhead in the mix.

Under the surface

The Harrison is a short, large, lake-fed Fraser tributary famous for big sea-run cutthroat and bull trout (Dolly Varden) that follow enormous autumn salmon runs, gorging on fry and eggs. Lake-buffered and relatively clear, it's one of the Lower Mainland's premier fly fisheries for trophy cutthroat in the fall, with steelhead and salmon in the mix.

Wading: Big lake fed river, strong current, gravel bars

  • Granite
  • Unconfined
  • Large river
  • Glide
Conservation note

Trophy sea-run cutthroat and bull trout / Dolly Varden (char, protected, C&R) following huge autumn salmon runs; salmon DFO-regulated. Clean-Drain-Dry.

The full read · show the working · for Cutthroat Trout · confidence 90%
How the 70 is built — score × weight = contribution
Temperature73 × 28%20.4
Flow60 × 22%13.2
Clarity85 × 18%15.3
Feeding Time70 × 13%9.1
Pressure75 × 7%5.3
Insect activity57 × 12%6.8
Conditions total= 70
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts