Big Thompson — Forest Canyon Headwaters (RMNP)
Forest Canyon (Big Thompson Headwaters, RMNP) — Fishing Report for April 27, 2026
Quick Stats
Flow: N/A (snow-covered, ungauged) | Trend: N/A | Fishability: Unfishable | Weather: Snow showers, high 35°F — more snow through Wednesday
The Bite
Forest Canyon is locked in deep winter right now, and there's no way to sugarcoat it: this water is simply not fishable. Snow showers are falling today with a high of 35°F, and the three-day forecast brings more of the same — overnight lows dropping to 23°F, snow showers continuing through at least Wednesday. The canyon floor won't see meaningful melt for weeks.
Water temperatures in the headwaters are hovering near freezing, there are no hatches, and the terrain — already steep and unmaintained in the best conditions — is buried under snowpack. Even if you could reach the creek, trout at these temperatures are essentially dormant and unresponsive. This is one of those rare situations where the right call is simply to wait.
It's worth noting that the broader basin is running well below normal on both snowpack and water-year precipitation — snowpack is a fraction of what a typical late April looks like. That does suggest Forest Canyon may open up a bit earlier than usual this summer once the remaining snow melts off, but that's still a late-June conversation at the earliest. For now, the mountain is closed for fishing.
What to Fish
- No fly recommendations applicable — conditions are unfishable
- When this water opens in summer: Royal Wulff #14–16 for attractor dry fishing
- When this water opens in summer: Elk Hair Caddis #14–16
- When this water opens in summer: Parachute Adams #16–18
- When this water opens in summer: Hare's Ear Nymph #16–18 as a dropper
Tactics & Rigging
There's nothing to rig up for Forest Canyon this week. When this section does come into shape — typically mid-to-late summer — the approach is simple: light tackle, small attractor dries, and short accurate casts to pocket water and plunge pools. A single dry fly or a dry-dropper with a small beadhead nymph 14–18" below is all you need. The fish are small but willing, and the canyon rewards patience and careful footwork more than fly selection.
Verify current RMNP regulations and any native cutthroat protections with CPW before your trip — barbless hooks and catch-and-release may be required in sections with Greenback Cutthroat presence.
Access & Logistics
Forest Canyon is off-trail backcountry terrain accessible from Trail Ridge Road — which itself is closed for the season and won't reopen until late May at the earliest. Do not attempt access. This is expert-only terrain even in ideal summer conditions; in snow and freezing temperatures, it's genuinely dangerous. Check NPS road status before planning any future trip.
For lower-elevation Big Thompson fishing closer to Estes Park and the canyon, stop by Estes Angler or Scott's Sporting Goods for current conditions, flies, and local intel.
Looking Ahead
Forest Canyon won't be worth revisiting until late June or July — check back as Trail Ridge Road opens and snowpack clears. In the meantime, lower-elevation Front Range streams and tailwaters are in prime spring form and worth your attention this week.