Colorado ·
Blue River Fly Fishing Report - August 9, 2026
BLUE RIVER
ReportAUG 9 — 16, 2026
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Flow
290CFS
BLUE RIVER BELOW GREEN MOUNTAIN RESERVOIR, CO
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Water Temp
—
Updated 2026-08-09
☀️
Weather
49–81°F
Areas Of Smoke
💧
Clarity
Clear
Check post-storm
Flow is running at 290 CFS below Green Mountain Reservoir with a gauge height of 3.94 ft — notably higher than the low-water conditions reported upstream near Silverthorne, so expect slightly deeper, faster runs with excellent visibility. Water clarity should be good, making precise presentations critical throughout the day.
What's Working — Hot Flies
Juju Baetis Tungsten #22
22
Black Zebra Midge(TBH) #20
20
Olsen's Peacock Blowtorch Barbless #22 - 24
22-24
Parachute - Blue Wing Olive #22
22
Top Secret Baetis #16
16
Egan's CDC Rainbow Warrior #22
22
Bionic Ant 2.0 - Black #16
16
Bionic Hopper - Tan #12
12
Roza's World Spain Perdigon Barbless #18 - 32
18
Corn-fed Caddis (CDC) Tan #20
20
Olsen's Hare's Ear Blowtorch Barbless #20 - 28
20
Bionic Hopper - Purple #12
12
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Midge | 20-24 | Heavy | 7 AM - 10 AM |
| Blue-Winged Olive (Baetis) | 20-22 | Moderate | 10 AM - 2 PM |
| Trico | 20-24 | Moderate | 8 AM - 11 AM |
| Terrestrial Ant | 14-16 | Moderate | 11 AM - 4 PM |
| Grasshopper | 10-12 | Light | 12 PM - 5 PM |
| Caddis | 18-20 | Light | 5 PM - 7 PM |
Best Time Window
- 6:30 AM - 10 AM: Early midge and Trico activity — nymph the seams with small tungsten patterns before the hatch, then switch to dries as fish begin rising in the flats.
- 10 AM - 2 PM: BWO hatch window extended by smoky, overcast skies — target rising fish in the slower glides with CDC emergers and parachute dries on a long, fine leader.
- 3 PM - 6 PM: Terrestrial prime time along grassy banks — work hoppers and ants tight to the edges before afternoon storm chances build and push fish down.
Guide's Tip
From the benchWith flows at 290 CFS, the Blue below Green Mountain is running with more push than the low-water sections upstream, so focus your nymphing in the seams along the main current edges rather than the dead center of the channel. Set your indicator depth at 1.5 to 2 times the water depth and use a 5X fluorocarbon tippet to get small midges and baetis patterns down quickly. Smoke in the forecast means diffused light all day — that's actually a gift for dry fly fishing, as fish won't be as spooked and BWO hatches can extend well past noon. If afternoon storms build, move to the banks with a hopper or ant pattern and work the structure hard before the lightning pushes you off the water.
Main Species
Rainbow Trout
Brown Trout
Mountain Whitefish
