Late October Blue River Fly Fishing Report: Conditions and Best Flies

Updated: October 30, 2025

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The Blue below Green Mountain is the last wild chapter of the river before it meets the Colorado, and it’s fishing steady and cold. Mornings start crisp, afternoons open up with sun and BWOs, and the canyon walls are glowing gold with what’s left of fall. The flows are stable, the water is clear, and the browns are still packing attitude after the spawn.

Fish are hugging structure and slow seams, taking small nymphs most of the day and swiping at streamers when shadows hit the bank. It’s quiet, cold, and exactly what late October in Colorado should feel like.

Conditions Summary

• Flow: 175 CFS ↓
• Water Temp: 38°F →
• Air Temp (5-day): 23–49°F ↓
• Clarity: Clear
• Pressure: Moderate
• Best Times: 11:00 AM–3:00 PM
• Dry Fly Score: ⭐⭐⭐
• Nymph Score: ⭐⭐⭐⭐
• Streamer Score:⭐⭐⭐

Flows are slightly down but consistent, with clean water and good visibility. Midday sun sparks short BWO hatches, while nymphing remains productive through slower pockets and seams. Early and late are prime streamer windows.

Top Flies for Late October

Dry Flies

• Parachute BWO #20–22; single on 6X; target risers mid-day when clouds hang.
• Parachute Adams #20; backup pattern for slower seams during BWO lulls.
• Griffith’s Gnat #22; use in flat water when trout rise softly to clusters.

Nymphs

• Beadhead Pheasant Tail #18; lead fly in two-fly rig; drift through walking-speed seams.
• RS2 Gray #20; trailer for soft takes in slower mid-depth water.
• Barr’s Emerger Olive #20; fish higher in the column when you see subtle rises.

Streamers

• Slumpbuster Olive #8–10; slow swing through canyon runs, tight to structure.
• Mini Dungeon Tan #8; short strips near rock walls early or late.
• Thin Mint Bugger #10; work transition water with slow retrieve.

How to Fish It: Start with a light two-nymph rig in the morning, drop to a single emerger or soft hackle once BWOs appear. In the last hour of light, tie on a streamer and swing across inside bends.

October Hatch List (mobile-friendly)

• Blue-Winged Olive (#20–22) | Size ★★★☆☆ | When: 11 AM–2 PM on overcast days | How: film emergers or soft-hackle swing through riffles
• Midges (#22–24) | Size ★★☆☆☆ | When: late morning to afternoon | How: double midge rig or dropper beneath a small dry
• October Caddis (#14–16) | Size ★★★★★ | When: 3–5 PM on sunny days | How: skate or twitch along banks and pocket seams

Tips for This Stretch

Fish are holding deep and close to structure; don’t overcast or wade too far. Keep your rig light and your drifts clean. Wind can pick up after lunch—tighten loops and shorten leaders. Watch for subtle head rises; they’re easy to miss in flat light.

Access Points

Tailwater Below the Dam; consistent flows, deep pockets, and structure-hugging browns in colder water.
Canyon Stretch; moderate hike with rewarding solitude, great streamer water below rock walls.
Confluence with the Colorado; wide, slower water, ideal for swinging streamers and covering ground.

Local Regulations and Notes

Flies and lures only; catch-and-release recommended. Watch for thin ice near shaded sections in the morning. Browns are post-spawn—avoid redds and shallow gravel. Flows remain low but steady; wade with caution.

FAQ on This Spot

Q: Is the brown trout spawn over?
A: Mostly, but a few stragglers remain in shallow gravel.

Q: What’s the best time to fish?
A: Late morning to early afternoon when seams warm.

Q: Are BWOs still hatching?
A: Yes, smaller (#22) olives are coming off mid-day on clouds.

Q: Best nymph combo right now?
A: Beadhead PT up top, RS2 or Barr’s Emerger dropper.

Q: Are streamers worth throwing?
A: Yes, early or late with slow swings through deeper slots.

Q: Indicator or tight-line?
A: Yarn or euro tight-line works best; plastic indicators spook fish.

Q: Is access limited?
A: Trail is open, but expect frost and icy rocks before noon.

Q: Can you float it?
A: Low flows—best fished on foot right now.

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