Tailwater · Mixed · Montana

Ruby River

Ruby River venue image

The Ruby below the reservoir is a small, intimate, brushy tailwater that grows browns a lot better than its size suggests.

Prime · Brown Trout
Sparkle Dun · 14-18
Primelive now
About as good as it gets
River steady at a fishable height. On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% confidence
What moved it
  • Level1.00 mLast reading 17h ago
  • Water temp10.3°C
  • ClarityClear
Today's fly
SD
Sparkle Dun14-18
High-confidence seasonal pick
Conditions on the water
Live gauge
Level
Steady
1.00 m
Last reading 17h ago
Water temp10.3°C
ClarityClear
Weather16°C
WindS 6 km/h
Pressure1017 hPa
Rain · recent0.2 mm
Rain · ahead0.0 mm

Live readings — water temperature is an estimate where the gauge does not record it.

Water temperature for Brown Trout
Ideal
10°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown 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
Excellent — water temperature is right today, though insect activity could be better.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 3 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

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Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
2
1
1
2
2
2
2
2
2
2
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
Brown Trout fly box
Permits & access
Permit required — see local rules.
  • Montana licence
  • Small, brushy, irrigation-controlled; access is contentious — verify before fishing.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Madison River
30 km
Brown trout · Rainbow trout
Jefferson River
33 km
Brown trout · Rainbow trout
Ennis Lake
35 km
Brown trout · Rainbow trout
Beaverhead River
50 km
Brown trout · Rainbow trout
Big Hole River
52 km
Brown trout · Rainbow trout · Brook trout
Gallery · 1
  1. Terrain map of the venue
    Terrain map
About this water

The Ruby below the reservoir is a small, intimate, brushy tailwater that grows browns a lot better than its size suggests. It's nearly as famous for its access fights as for its fishing — the public-access question here has been argued in court, so confirm where you can legally stand before you wade in. Flows swing with irrigation demand, which means the river you fished last week may not be the one you find today.

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

EPA ATTAINS assessment unit 'Ruby River' (MT41C001_010), 2021 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: Temperature, Sediment, Nutrients, Habitat Alterations, Hydrologic Alteration. 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) · MT41C001_010

The full read · show the working · for Brown Trout · confidence 90%
How the 85 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity61 × 12%7.3
Conditions total= 85
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Apple MapsGoogle Maps
Seasons & zones
  • TroutThird Saturday of May → Last day of February
Related guides
Euro Nymphingsubsurface methods
Booking & contacts