Tailwater · Mixed · Northern California, US

Lower Stanislaus River

Knight's Ferry covered bridge, Stanislaus River, California
Good · Rainbow Trout
RS2 · 18-22
Goodlive now
A proper day on the water
River dropping into shape after a lift. Fishing well — get there before it drops out.
90% confidence
What moved it
  • Level12.85 mDropping after lift
  • Water temp13.0°C
  • ClarityColouredClearing
Today's fly
RS2
RS218-22
High-confidence seasonal pick
Conditions on the water
Live gauge
Level
Steady
12.85 m
Dropping after lift
Water temp13.0°C
ClarityColoured
Weather13°C
WindNE 7 km/h
Pressure1018 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

Live readings only. Trends shown where the gauge supports them.

Water temperature for Rainbow Trout
Ideal
13.0°Cideal 10–18°C
0°14°28°

A dam sets this river's temperature, not the weather, so it can shift several degrees within hours when the release changes. Measured 4 km from the gauge. It also warms as it runs away from the dam.

How to fish it · for Rainbow 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 temperature is right today, though time of day could be better.
Likely species
Mayflies
Chironomids
Gammarids
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 7 active hatches hour by hour as a supporter.

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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 4 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 · October 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
Western Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Pale Morning DunHatch
2
3
3
2
TricoHatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2

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

Ranked for today
Fly box · Rainbow Trout
Permits & access
Permit required — see local rules.
  • Open all year; barbless, with low-flow / steelhead closures — check CDFW
  • ESA-listed steelhead present: handle with care
  • Flow tracks Goodwin/New Melones releases.
What's coming
Plan ahead
5-day outlook
Other water nearby · 1
Lower Mokelumne River
55 km
82
Rainbow trout
Gallery · 2
  1. Knight's Ferry covered bridge, Stanislaus River, California
  2. Terrain map of the venue
    Terrain map
Conservation note

Holds ESA-listed Central Valley steelhead. We name their presence and leave it there — no catch score on listed fish, no targeting nudge. Handle any you meet with real care.

Water quality · US Clean Water Act
  • Aquatic life: Impaired
  • Fish consumption: Impaired
What this classification means

Fish consumption: Consumption advisory (Mercury) — fish for sport, not the table.

EPA ATTAINS assessment unit 'Stanislaus River, Lower' (CAR5353000019980817151834), 2024 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Temperature, Mercury. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · CAR5353000019980817151834

The full read · show the working · for Rainbow Trout · confidence 90%
How the 79 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity70 × 18%12.6
Feeding Time60 × 13%7.8
Pressure75 × 7%5.3
Insect activity65 × 12%7.8
Conditions total= 79
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Booking & contacts