Reservoir · Mixed · Montana

Clark Canyon Reservoir

Clark Canyon Reservoir venue image

Clark Canyon is the big sagebrush-rimmed reservoir that feeds the Beaverhead tailwater below it, and it grows the heavy browns and rainbows that make the Beaverhead famous.

Fair · Rainbow
Callibaetis Nymph · 12-16
Fairlive now
Reasonable summer fishing likely at Clark Canyon Reservoir
Glassy and bright — hard work without a breeze. Hard work without breeze. Look for the dimples.
51% confidence
What moved it
  • WindSE 5 km/hCalm
Today's fly
CN
Callibaetis Nymph12-16
High-confidence seasonal pick
Conditions on the water
Live gauge
Wind
Calm
SE 5 km/h
N
SE
from the south-east
WaveFlat calm
Water temp—
Air temp20°C
CloudClear
Pressure1017 hPa
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Rainbow
When
Conditions are not ideal but fishable at Clark Canyon Reservoir. Flat calm means fish may be spookier — longer leaders and subtler flies will help.
Where
Start with Callibaetis Nymph (12-16) on a slow figure-of-eight retrieve. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely.
The plan
Plan A

Start with Callibaetis Nymph (12-16) on a slow figure-of-eight retrieve. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely.

Plan B

Fish early and late, try deeper during the heat of the day with a fast-sinking line.

Watch for

Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.

Bank

Flat calm suits bank fishing near features — points, weed beds, and inflows where fish patrol.

Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 5 with Pro.

Start free trial

14-day free trial. Cancel anytime.

Through the year
0–3 scale · July 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
Gray DrakeHatch
2
2
CallibaetisHatch
2
3
3
3
2
Hexagenia (Western)Hatch
2
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
Rainbow fly box
Permits & access
Permit required — see local rules.
  • Montana stillwater regulations — check FWP.
What's coming
Plan ahead
5-day outlook
Condition match
52%
Cloud25%
Wind65%
Temp60%

A reasonable day here, though cloud isn't quite in the sweet spot.

Other water nearby · 3
Beaverhead River
28 km
Brown trout · Rainbow trout
Red Rock River
57 km
Brown trout · Rainbow trout
Big Hole River
60 km
Brown trout · Rainbow trout · Brook trout
Gallery · 1
  1. Terrain map of the venue
    Terrain map
About this water

Clark Canyon is the big sagebrush-rimmed reservoir that feeds the Beaverhead tailwater below it, and it grows the heavy browns and rainbows that make the Beaverhead famous. It's open, windy water out near Dillon — you fish it from a boat, throwing leeches and chironomids and Callibaetis to fat reservoir fish that have a lot of food and grow fast. It's not pretty in the postcard sense, just productive, and the trout are thick-shouldered and strong. Spring and fall are the times; midsummer the surface warms and the fishing goes deep.

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

EPA ATTAINS assessment unit 'Clark Canyon Reservoir' (MT41A002_010), 2021 Integrated Report. Aquatic Life use: Not Supporting. Listed impairment causes: 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) · MT41A002_010

Why this score
  • summer conditions with clear skies and calm wind.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout1 January → 31 December
Related guides
Big Stillwater Playbookreservoir tacticsReservoir Entomologymatching the hatchThermal Layers & Troutreading depth and temperature
Booking & contacts