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Blue River (below Dillon Reservoir, Silverthorne): USGS Gauge and Hatch Chart

CO · Tailwater · USGS site 09050700

Gauge

Hatch Window's starter list uses USGS site 09050700 for this water. Gauge coordinates: 39.625556, -106.065833. This page does not show live conditions. For current streamflow and gauge height, see the official USGS page for site 09050700. USGS water data is provisional and may be revised.

Hatch chart entries tagged tailwater in the Mountain West

These are the curated chart entries tagged for Mountain West waters and the tailwater water type. They are general entries, not a report specific to this river.

HatchTypical monthsPatterns
MidgesJanuary to DecemberZebra Midge (nymph, size 18-22); Griffith's Gnat (dry, size 18-22); Rojo Midge (nymph, size 20-24)
Blue-Winged OliveFebruary to April, September to NovemberParachute Adams (dry, size 16-20); Pheasant Tail Nymph (nymph, size 16-20); CDC BWO Sparkle Dun (emerger, size 18-20)
Caddisflies (general)April to AugustElk Hair Caddis (dry, size 14-18); Sparkle Pupa (emerger, size 14-18); LaFontaine's Deep Sparkle Pupa (nymph, size 14-16)
Pale Morning DunJune to AugustPMD Sparkle Dun (emerger, size 16-18); PMD Parachute (dry, size 16-18); PMD Pheasant Tail (nymph, size 16-18)
TricoJuly to SeptemberTrico Spinner (dry, size 20-24); CDC Trico Dun (dry, size 20-24)
Hoppers, ants & beetlesJuly to SeptemberDave's Hopper (terrestrial, size 6-10); Chernobyl Ant (terrestrial, size 8-12); Foam Beetle (terrestrial, size 12-16)
Baitfish / sculpins (streamer season)March to April, October to NovemberWoolly Bugger (streamer, size 4-10); Sculpzilla (streamer, size 2-6)
Scuds & SowbugsJanuary to DecemberScud (olive/tan) (nymph, size 14-18); Sowbug (nymph, size 14-18)
Yellow Sally (Little Yellow Stonefly)May to JulyYellow Sally Dry (dry, size 14-16); Yellow Stimulator (dry, size 14-16); Little Yellow Stone Nymph (nymph, size 14-16)
Mahogany DunSeptember to OctoberMahogany Dun Parachute (dry, size 16-18); Pheasant Tail Nymph (nymph, size 16-18)

See also the full hatch chart.

Check local regulations. Seasons, gear rules, closures and access vary by water and change often. Check current regulations and conditions for the water you plan to fish, and carry a valid license.
About this page. Hatch timing varies by year, elevation and water temperature. Months here are typical ranges from the Hatch Window curated chart, a starting point and not a live report of what is hatching today. Hatch Window is a free fly-fishing companion app from Baker Ventures LLC with a built-in version of this chart, plus streamflow from USGS and weather from Open-Meteo. Data source: Hatch Window source files src/data/hatches.ts and src/data/spots.ts, commit c45001f.