Tailwater · Limestone · Montana

Bighorn River

Bighorn River venue image
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The Bighorn below Yellowtail Dam is one of the great tailwaters anywhere — cold, fertile, stable water year-round, packed with big browns and rainbows that eat all day if you do your part.

Species

A proper day on the water

River high but settled. Match the colour and fish the seams.

75% confidence in this read
Water temperature for brown trout
Cool — slow
9°C est.ideal 1016°C
0°14°28°
Why this score · for brown trout
  • Temperature8228% weight
  • Flow8022% weight
  • Clarity9518% weight
  • Feeding Time5013% weight
  • Pressure807% weight
  • Insect activity6212% weight
Conditions
Level
18.12 m
Water temp
9.0°C
Estimated
Clarity
Clear
Air temp
23°C
Wind
E 12 km/h
Light breeze
Pressure
1012 hPa
Rain · 48h
0.0 mm
No meaningful rain
Rain · ahead
1.2 mm
No meaningful rain · next 48h

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

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
Good — water clarity is right today, though time of day could be better.
Through the year
0–3 scale · June 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
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Western Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Pale Morning DunHatch
2
3
3
2

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

Gallery · 1
  1. Terrain map of the venue
    Terrain map
Permits & access
Permit required — see local rules.
  • Open all year (tailwater)
  • Fishability is set by the Yellowtail Dam release, not the weather.
Directions
About this water

The Bighorn below Yellowtail Dam is one of the great tailwaters anywhere — cold, fertile, stable water year-round, packed with big browns and rainbows that eat all day if you do your part. The menu is sowbugs, scuds, and midges, with serious Baetis and PMD hatches when the season turns. Here you watch the dam release, not the sky; the weather barely gets a vote.

Under the surface

The Bighorn that anglers mean begins at the Yellowtail Afterbay Dam near Fort Smith, where cold, clear, nutrient-rich water is let out from the depths of a reservoir backed up through seventy-odd miles of limestone canyon. That limestone is the secret: it loads the water with the minerals that grow insects by the acre, and the first thirteen miles below the dam, running through the Crow Reservation toward Hardin, are about as rich a trout factory as exists in Montana. The river here is a big, even, gravel-bottomed tailwater — long riffles, glassy flats and deep outside bends winding across an open valley of cottonwood and sage. The flow is steady because a dam decides it, not the weather. Wading is comfortable on firm gravel, though the Bighorn is bigger and pushier than it first appears.

Wading: Deeper, pushier water than it appears

  • Limestone
  • Unconfined
  • Pool riffle
Seasons & zones
  • Trout1 January → 31 December
Other water nearby · 2