Waterton Canyon Fly Fishing Report – Tricos, Bikes & Stealth Tactics (Sept 17, 2025)

Waterton Canyon on the South Platte River isn’t just another spot on the map, it’s a rite of passage for fly fishing enthusiasts. If you’re looking to sharpen your skills, this is the place. The canyon’s reputation as one of the most technical fisheries around isn’t just for show; it’s earned. 

Waterton in October feels like Denver’s secret backcountry — cool mornings, canyon walls glowing gold, and trout quietly sipping midges like nothing else matters. The crowds thin, the fish smarten up, and the canyon gives you that rare mix of peace and precision.

 

• Flow: 92 CFS below Strontia Springs ⬇
• Water Temp: 52°F steady
• Air Temp: 40–70°F
• Clarity: Clear
• Pressure: Low–Medium (weekends busier near the dam)
• Best Times: 9 AM–2 PM (midday BWOs, midges all day)
• Dry Fly Score: ⭐⭐⭐
• Nymph Score: ⭐⭐⭐⭐
• Streamer Score: ⭐⭐

Flows are low, clear, and ideal for light rigs. Cooler temps have midges and BWOs dominating, and fish are feeding predictably mid-column. Mornings can be slow, but once the canyon warms, trout slide into riffles and seams.

 

 

• Dry Fly: Hi-Vis BWO Parachute #20–22, CDC Trico Spinner #22–24
• Nymph: RS2 (gray) #22, Barr’s Emerger #20–22, Black Zebra Midge #22
• Streamer: Mini Leech (olive) #10–12, Thin Mint Bugger #10

 

• Midday BWOs are your best bet — fish riffles and tailouts once the sun hits the canyon.
• Keep leaders long (9–12 ft) and light (5–6X).
• Use small indicators or dry-dropper rigs for stealthy drifts.
• Afternoon shadows along canyon walls can trigger streamer takes.
• Bring a bike or good boots — the farther you walk, the better it fishes.

• Open sunrise to sunset, foot or bike access only.
• Catch-and-release encouraged.
• Respect bikers and hikers — multi-use trail.

• What time of day is best in October?
  Midday when the canyon warms and BWOs hatch.
• What’s the best rig right now?
  A light nymph rig: RS2 and Zebra Midge under a small indicator.
• Do streamers work here?
  Occasionally in shaded edges late afternoon.
• How’s the crowding?
  Light during the week, moderate on weekends.
• What tippet size should I use?
  5–6X for dries and nymphs, 4X for small streamers.
• Any dry fly action?
  Yes, BWOs mid-day and the occasional Trico rise early.
• Best section for beginners?
  Mile 2–3 — consistent structure and easy wading.
• Is the canyon open all year?
• Yes, though icy conditions can limit access in winter.