Blue River Fishing Report near Dillon Dam - Outstanding Winter Tailwater Strategy

The Blue River below Dillon Dam is a classic Colorado tailwater that stays open and fishable all winter. Water is cold, clarity is clear, and trout rely on a consistent diet of midges, small baetis, and mysis shrimp when conditions allow. Right now, flows are low, and water temps are near winter lows — meaning the feeding window is condensed, and technical precision is rewarded.

Updated: February 3, 2026

The Blue below Dillon fishes like a technical classroom in winter. Clear tailwater flows and consistent structure create predictable holding water, but trout see everything. Fish stack into deep seams, slow inside edges, and tailouts where depth and drift matter more than pattern changes.

This is not water to rush or experiment on. Pick one lane, adjust weight until you tick bottom occasionally, and stay put. Ignore shallow riffles entirely. When the sun reaches the water late morning, trout feed just enough to reward disciplined presentations, especially in softer edges and mid channel seams.

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Conditions Summary

(Data from USGS streamgage #09050700)

Flow: 105 CFS. Stable winter tailwater releases concentrate trout in deep seams and tailouts.

Water Temperature: No Data °F

Air Temperature: 39 °F

Wind: 6 to 12 mph

Clarity: Clear

Crowds: High

Primary Hatch: Midges

Best Window: 11 a.m. to 2 p.m.

Overall Rating: Technical winter fishing with consistent but pressured opportunities

Weather

Winter weather around Summit County remains cold, with strong overnight freezes and muted daytime warming. Calm, sunny days near or above freezing are the best for triggering midge activity and trout response. Wind can shorten the bite window quickly, especially on clear days.

Top Flies in Your Box This Week

Primary Method: Nymphing | Primary Hatch: Midges

1. Zebra Midge 18 to 22
   Fish deep through slow tailouts and seams.
2. Black Beauty 20 to 24
   Dead drift tight to bottom in clear water.
3. RS2 gray 18 to 22
   Use when fish suspend slightly off bottom.
4. Mercury Midge 20 to 22
   Effective in pressured tailwater conditions.
5. Top Secret Midge 20 to 24
   Drift through soft inside edges.

Secondary Hatch: Baetis

1. Barrs Emerger 18 to 20
   Fish mid column late morning.
2. Pheasant Tail 16 to 18
   Dead drift through deeper runs.
3. Split Case BWO 18 to 20
   Use during calm afternoons.

Attractor and Streamer

1. Mini Leech black or olive 10 to 12
   Very slow strip near deeper banks.
2. Woolly Bugger olive 8 to 10
   Short swings through softer water. (Pro tip: snip off the flashing, it hooks anglers not fish here in the Rockies ;) ) 

Pro Rig of the Week: Dillon Dam Tiny Water Column Rig

Indicator: Very small yarn or minimal micro indicator

Lead Fly: Zebra Midge #22

Dropper: Top Secret Midge #22–24

Weight: One micro split shot just enough to tick bottom occasionally

Target Water: Edges, seams, and slower “walking speed” water very near structure

Blue River Hatch Chart – February

Download the Blue River Hatch Chart

Access Points

Below Dillon Dam | 📍 Locals Rating ⭐️⭐️⭐️⭐️⭐️ 5.0
Premier tailwater access with consistent winter holds.

Silverthorne Stretch | 📍 Locals Rating ⭐️⭐️⭐️⭐️ 4.5
Deep seams and tailouts near town.

Rainbow Park Area | 📍 Locals Rating ⭐️⭐️⭐️⭐️ 4.0
Reliable winter structure with easy access.

Lower Blue Pull-Offs | 📍 Locals Rating ⭐️⭐️⭐️ 3.5
Productive water with higher pressure.

Green Mountain Road Stretch | 📍 Locals Rating ⭐️⭐️⭐️ 3.0
Less consistent winter holding lanes.

Stop Here After the River

Angry James Brewing Co. (Silverthorne)
A relaxed post-river hangout with warm food-truck meals, mountain-town energy, and reliably good beer.
What to order: The Resolute IPA with a rotating hot entrée from the food truck lineup.

Local Regulations and Notes

• Tailwater flows change; always check the release before fishing
• Extremely clear water requires long leaders and 6X tippet
• Sight-fishing is possible but demands quiet wading
• Respect town pathways and private property along the corridor

FAQ

Is the Blue River Below Dillon Dam Good for Fly Fishing in Winter?

Yes. The Blue River below Dillon Dam offers consistent winter trout fishing due to stable tailwater flows. Trout hold predictably in deeper seams and feed during short midday windows when conditions align.

How Technical Is Fly Fishing the Blue River Below Dillon Dam?

Very technical. Ultra-clear water, steady flows, and heavy angling pressure require precise drifts, small flies, and careful depth control. This stretch rewards patience and punishes sloppy presentations.

Q: Is the Blue River below Dillon Dam good in winter?
A: Yes. Cold but consistent flows make it one of Colorado’s most predictable winter tailwaters.

Q: What weight rod should I bring?
A: A 4 or 5 weight with a long leader setup is ideal for this technical water.

Q: Are dries an option?
A: Rarely, but on the warmest calm afternoons you might find isolated midge clusters.

Q: What is the biggest mistake anglers make here?
A: Heavy footsteps and heavy rigs. Everything here requires subtlety.

Q: Does the flow matter more on a tailwater?
A: Yes. Even small changes from the dam can shift where trout stack.

Q: When is the best time of day?
A: Midday, when water temps rise the most.

Q: Is the Blue River good in winter?
A: Yes. It is one of the most consistent winter tailwaters in Colorado, but it is very technical.

Q: What is the biggest mistake anglers make here?
A: Fishing too heavy or too fast. Subtle depth control matters more than fly changes.

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: Does wind ruin the fishing?
A: It can. Wind makes precise drifts extremely difficult on this stretch.

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

Companion Article

Colorado Winter Trout Feeding Behavior in Clear Tailwaters