Tailwater · Sandstone · Arizona, US

Colorado River — Lees Ferry

The Colorado River flowing through red-rock Marble Canyon at Lees Ferry, Arizona, with the Vermilion Cliffs rising behind.
Today · About as good as it gets
Czech Nymph
Forecast · Today
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
70% projected
Today's fly
Czech Nymph
Czech Nymph
Conditions on the water · Today
Live gauge
Level
Steady
2.24 m
Dropping in the last 6h
Water temp17.6°C
ClarityClear
Weather15°C
WindN 4 km/h
Pressure1030 hPa
Rain · recent4.5 mm
Rain · ahead4.5 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Rainbow Trout
Ideal
18°C est.ideal 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. 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
Water at 19.3°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Gammarids
Hatch timeline · todayQuiet day

Low insect activity predicted today

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 · 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
Local fly shops: Lees Ferry Anglers
Permits & access
Permit required — see local rules.
  • Open all year
  • Arizona licence required; check AZGFD reach-specific rules and the walk-in vs boat-access sections.
What's coming
Plan ahead
5-day outlook
Water here at 19.3°C. Nothing cooler within range.
Gallery · 2
  1. The Colorado River flowing through red-rock Marble Canyon at Lees Ferry, Arizona, with the Vermilion Cliffs rising behind.
    Colorado River at Lees Ferry Marble Canyon, Grand Canyon National Park, Arizona
  2. Terrain map of the venue
    Terrain map
Water quality · US Clean Water Act
  • Aquatic life: Impaired
What this classification means

EPA ATTAINS assessment unit 'Colorado River, from GLEN CANYON DAM to LEES FERRY' (AZ14070006-001_00), 2024 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Metals Other Than 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) · AZ14070006-001_00

The full read · show the working · for Rainbow Trout · confidence 80%
How the 32 is built — score × weight = contribution
Temperature48 × 28%13.4
Flow80 × 22%17.6
Clarity85 × 18%15.3
Feeding Time65 × 13%8.5
Pressure75 × 7%5.3
Insect activity30 × 12%3.6
Conditions total= 64
Can you trust it?
Water temperaturelive gauge readinggauge
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Cooler water — back toward the 10–18 °C ideal band — would lift the score and ease welfare.
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