Colorado River Fly Fishing Report - August 8/23/2025
COLORADO RIVER FLY FISHING REPORT
Upper Colorado — Glenwood Springs to Kremmling corridor
Report Date: August 23, 2025 | Next Update: August 30, 2025
Current River Conditions
Late‑summer pattern: water is lower and clearer than spring runoff, insect activity is driven by terrestrials and evening caddis—fish the edges and foam lines during hatch pulses. Keep an eye on water temperature; stop fishing when temps reach or exceed 68°F to protect trout.
Flows & Clarity
Flow: Low-to-moderate for late summer (check current USGS/Corps reads for your section)
Water Clarity: Generally clear; thunderstorms can stain pockets quickly
Tip: Floating sections still fish well, but wading is productive near seams and eddies
Flow: Low-to-moderate for late summer (check current USGS/Corps reads for your section)
Water Clarity: Generally clear; thunderstorms can stain pockets quickly
Tip: Floating sections still fish well, but wading is productive near seams and eddies
Water Temperature
Typical late‑Aug range: mid‑50s to upper‑60s°F (13–20°C)
Threshold: 68°F (20°C) — if water approaches this, prioritize trout safety (shorter fights, keep fish in water)
Typical late‑Aug range: mid‑50s to upper‑60s°F (13–20°C)
Threshold: 68°F (20°C) — if water approaches this, prioritize trout safety (shorter fights, keep fish in water)
Weather
Pattern: Warm days with possible afternoon thunderstorms; mornings calm and best for dry/dropper tactics
Wind: Variable — expect more breeze on wider runs in the afternoon
Pattern: Warm days with possible afternoon thunderstorms; mornings calm and best for dry/dropper tactics
Wind: Variable — expect more breeze on wider runs in the afternoon
Access & Safety
Boat ramps operational; private sections may have restrictions
Respect posted closures on tributaries and spawning protections; use life jackets on floats
Boat ramps operational; private sections may have restrictions
Respect posted closures on tributaries and spawning protections; use life jackets on floats
Hatch Chart & Insect Activity (late August)
| Insect | Size | Activity Level | Prime Time / Notes |
|---|---|---|---|
| Terrestrials (Hoppers, Beetles, Ants) | #6–12 (hoppers), foam terrestrials | Heavy ⭐⭐⭐⭐ | Warm afternoons; shorelines, foam seams — great for hopper-dropper rigs |
| Caddis (adult & pupa) | #14–18 | Moderate ⭐⭐⭐ | Evenings and low-wind windows; skitter dries or emergers under an indicator |
| Blue‑winged Olives (small baetis) | #16–20 | Light–moderate ⭐⭐⭐ | Cool mornings and overcast days — parachute BWO and emerger patterns |
| Midges | #18–22 | Steady ⭐⭐ | All day in slow tails and pools; euro nymphing or small midge patterns |
| Stoneflies / Salmonflies | #6–10 | Low ⭐⭐ | Mostly a spring event here — not a driver in late August |
| Small Mayflies / PMDs | #14–18 | Light ⭐⭐ | Less consistent — carry a few PMD patterns just in case |
Recommended Flies (matched to stocked fly patterns)
Below are the top patterns to pack for the Upper Colorado in late August. I've matched each recommendation to flies from the fly sheet so you can click through and order or inspect profiles.
| Pattern | When to Use | Link |
|---|---|---|
| Hopper / Terrestrial | Afternoon terrestrials — top of a hopper‑dropper | Taylor's Fat Albert - Tan |
| Hopper / Attractor (small) | Shoreline sipping trout, late afternoon | Fancy Pants Hopper - Tan |
| Caddis Dry / CDC | Evening skittering and emergence windows | Corn‑fed Caddis (CDC) - Olive |
| BWO / Small Mayfly | Cool mornings, overcast hatch windows | Parachute - Blue Wing Olive |
| PMD / Emerger | Late morning hatch pulses | Split Case - PMD |
| Nymph — Pat's Rubber Legs (stonefly imitation) | Heavy-strike nymphing on riffles and tailouts (dropper or indicator) | Tungsten Pat's Rubber Legs - Tan & Brown |
| Nymph — Pheasant Tail (general mayfly nymph) | Indicator or Euro setups in runs and seams | Pheasant Tail Tungsten |
| Perdigon / Point Fly | Tight‑line and Euro nymphing for picky fish in fast water | Egan's Warrior Perdigon - Rainbow |
| Streamer — Sculpin / Baitfish | High‑energy takes in deeper runs, around structure | Coffey's Articulated Sparkle Minnow (Sculpin #4) |
| Streamer — Heavy / Meat | Low-light or stained water; work the banks | Sculpzilla - Olive |
| Jig / Big Nymph (deep runs) | Fish deep seams and current seams under an indicator | Jiggy Pat's |
Tactics & Tips from the Guide Box
- Morning: fish nymph rigs deep in faster water and seams. Use a heavy point fly (Perdigon or tungsten Pheasant Tail) with a softer dropper behind for natural presentation.
- Midday/Afternoon: switch to hopper‑dropper setups along banks and foam lines. A big hopper on the surface draws attention; a tungsten Pat's Rubber Legs or jig nymph below finds the willing fish.
- Evening: float dries (caddis, BWO) in calmer water. Skitter the caddis or set an emerger pattern under a small indicator when you see subsurface activity.
- Streamers: work structure—strip in short bursts, pause to let the fly fall. Brown/olive sculpin or articulated minnow patterns produce the largest strikes.
- Fish care: keep trout in the water, use barbless hooks, and avoid long fights when water temp approaches 68°F.
- Midday/Afternoon: switch to hopper‑dropper setups along banks and foam lines. A big hopper on the surface draws attention; a tungsten Pat's Rubber Legs or jig nymph below finds the willing fish.
- Evening: float dries (caddis, BWO) in calmer water. Skitter the caddis or set an emerger pattern under a small indicator when you see subsurface activity.
- Streamers: work structure—strip in short bursts, pause to let the fly fall. Brown/olive sculpin or articulated minnow patterns produce the largest strikes.
- Fish care: keep trout in the water, use barbless hooks, and avoid long fights when water temp approaches 68°F.
Quick Gear Checklist
Rods & Lines
4–6 wt for dries & nymphs; 6–8 wt for big streamers
Floating line + sink tips for streamer work
4–6 wt for dries & nymphs; 6–8 wt for big streamers
Floating line + sink tips for streamer work
Tippet & Leaders
5X–6X for dries, 3X–4X for streamers
Long leaders (10–12') for picky fish on clear water
5X–6X for dries, 3X–4X for streamers
Long leaders (10–12') for picky fish on clear water
Accessories
Thermometer, nippers, forceps, polarized shades, wading staff, PFD for float trips
Thermometer, nippers, forceps, polarized shades, wading staff, PFD for float trips
