Blue River Below Green Mountain Reservoir Fly Fishing Report | Winter Tailwater Conditions

The Blue River below Green Mountain Reservoir settles into a true winter tailwater fishery once January sets in. Cold mornings, clear water, and predictable trout behavior define this stretch right now. While it does not fish fast or easy, it offers consistent opportunities for anglers willing to slow down and fish with precision. Pressure is moderate, but the river spreads anglers out well.

This section of the Blue River rewards anglers who understand winter tailwater rhythm. Trout stack in deeper lanes, feed selectively, and respond best to clean drifts with small midges and mysis patterns. Midday warmth drives the only reliable feeding window, and success comes from patience rather than aggressive fly changes.

Updated: January 7, 2026

The Blue River below Green Mountain Reservoir is running clear and cold with stable winter releases. Trout are holding deep and tight to structure, with movement increasing slightly during midday when sun reaches the water. Expect technical fishing, but consistent action when depth and drift are correct.

This week’s Blue River fly fishing report emphasizes subtlety. Midge larvae and mysis shrimp dominate the food supply. Trout are present and feeding, but sloppy drifts or excessive weight will shut things down quickly. Fish slow seams, inside bends, and deeper troughs where current speed drops.

Listen to the Audio Overview

Conditions Summary

Flow: ~350 to 450 CFS below Green Mountain Reservoir, stable early-winter release
Water Temperature: Mid 30s to low 40s
Air Temperature: Mid 20s to upper 30s
Clarity: Very clear
Crowds: Light
Best Window: 11 a.m. to 3 p.m.
Fishing Type Focus: Winter nymphing with small midges and baetis

Weather

Expect cold mornings with brief midday warming. Calm, sunny days fish best. Wind or heavy cloud cover shortens feeding windows significantly and pushes trout tighter to the bottom.

Top Flies in Your Box This Week

• Black Beauty 20 to 24
• Zebra Midge (black or red) 20 to 22
• Mercury Midge 20 to 22
• RS2 (black or gray) 20 to 22
• WD-40 20 to 22
• Juju Baetis 20 to 22
• Small Pheasant Tail 18 to 20
• Scud (olive or gray) 14 to 18

Pro Rig of the Week: Green Mountain Deep Slot Rig

Indicator: Small yarn or ultra-sensitive pinch-on
Lead Fly: Mysis Shrimp 16 to 18
Dropper: Black Beauty or Zebra Midge 22 to 24
Weight: One small BB placed 10 to 12 inches above the lead fly
Target Water: Slow seams, inside bends, and deep mid-river troughs

Hatch Chart for January 

Download the Blue River Hatch Chart.

Access Points

Blue River Below Green Mountain Dam ⭐⭐⭐⭐⭐
The premier tailwater stretch with deep seams, canyon structure, and consistent winter flows. Ideal for technical nymphing with small patterns.
Rating: Five gold stars

BLM Access – Canyon Stretch ⭐⭐⭐⭐☆
Mixed pocket water and longer troughs that hold trout during the coldest months. Less pressured than the dam section and excellent for mobile anglers.
Rating: Four gold stars

Confluence Area Downstream ⭐⭐⭐⭐☆
Where the river flattens and widens slightly, offering soft edges and slower winter lanes. Productive on days with light cloud cover.
Rating: Four gold stars

Stop Here After the RiverAngry James Brewing Co.

Angry James Brewing Co. (Silverthorne)
A warm, relaxed local brewery perfect after a day in the cold canyon. Expect big mountain vibes, community tables, and comfort-focused après energy.
What to order: The Resolute IPA and the rotating food truck’s signature warm dish.

Local Regulations and Notes

• Watch for changing dam release flows before entering canyon water
• Shelf ice can form along shaded edges
• Wading is technical; use caution on slick canyon rock
• Keep distance from other anglers due to narrow channel geometry

Companion Article

Colorado Winter Trout Feeding Behavior in Clear, Low-Flow Rivers

FAQ

Is the Blue River Below Green Mountain Good for Fly Fishing in Winter?

Yes. The Blue River below Green Mountain Reservoir offers consistent winter trout fishing for anglers willing to fish slowly and precisely. Feeding windows are short but reliable during calm midday conditions.

How Technical Is the Blue River in Winter?

Moderately to highly technical. Trout are selective, and success depends on depth control, clean drifts, and small flies rather than aggressive tactics.

Q: Is the Blue River below Green Mountain Reservoir good in winter?
A: Yes. Stable tailwater flows make it one of the most reliable cold-season fisheries in Colorado.

Q: What flies catch the most fish here?
A: Small midges, baetis nymphs, and subtle emergers are the bread and butter.

Q: Do streamers work?
A: Occasionally. Small leeches can move fish in deep slots on overcast days.

Q: How technical is this section?
A: Very. Clear water and slow current require stealth and precision.

Q: What is the best time of day?
A: Midday, when sunlight and slight temperature bumps activate midges.

Q: Can I sight-fish?
A: Yes in many sections, but trout spook easily in winter clarity.

Q: Is the Blue River below Green Mountain good in winter?
A: Yes. It is one of the most consistent and least crowded winter tailwaters in Colorado.

Q: How technical is this stretch compared to Dillon Dam?
A: Slightly less pressured, but still technical. Depth control and drift quality matter.

Q: Are dry flies an option right now?
A: Rarely. Subsurface midge patterns dominate winter success.

Q: What leader and tippet setup works best?
A: Long leaders with 5X to the lead fly and 6X to the midge dropper.

Q: Do scuds matter here in winter?
A: Yes. Scuds are an important secondary food source in this tailwater.

Q: When does the bite shut down?
A: Typically mid-afternoon once shadows and colder air settle into the canyon.