Upper Poudre: Rustic to Big South Trailhead

Upper Canyon — Fishing Report for April 27, 2026

Quick Stats

Flow: 173 CFS | Trend: Rising | Fishability: Fair | Weather: Chance snow showers, high 47°F

The Bite

A late-April snow cycle is rolling through the upper canyon today, and it's going to reshape what would otherwise be a promising week on the Poudre. Flows are sitting at 173 CFS — right in the middle of the seasonal range — and have been creeping up about 7.5% over the past 24 hours. That's manageable wading, but the cold, unsettled weather through at least Tuesday will keep water temps down and fish behavior more sluggish than the calendar might suggest.

Here's the nuance worth knowing: the upper canyon is running on a very lean water year. Snowpack across the basin is sitting at just 16% of normal, and overall precipitation since October is at 66% of normal. That means the spring runoff pulse will likely be modest and short — which is actually good news for June and July fishability. For now, though, the current rise is driven more by these passing storm cycles than a full snowmelt surge, so flows should stay manageable rather than blowing out.

The BWO hatch that defines April on this water is still possible — overcast skies during a snow shower break could trigger a short afternoon window — but don't plan your day around it. Midges will be the more reliable surface activity in the morning, and nymphing through the deeper pockets and runs will be the consistent producer. The Grannom caddis is just beginning to show in late April, but cold temps today will push that emergence back. Save the dry-fly optimism for Wednesday when a brief warm-up is in the forecast.

What to Fish

• Pheasant Tail Nymph #16-18 — Point fly in a double-nymph rig; let it ride the bottom of deeper runs with a natural, drag-free drift
• Prince Nymph #14-16 — Anchor fly option with more weight and visibility in slightly off-color water
• Zebra Midge #20-22 — Dropper off the Prince in slower tailouts and pools; effective through midday
• Parachute BWO #18-20 — Worth having rigged if skies go flat gray between snow showers; fish the slower water near current seams
• Black Stonefly Nymph #14-16 — Active in riffles; a solid alternative anchor when fish seem uninterested in the Pheasant Tail
• RS2 Emerger #20 — Trail this 12–16" below a Parachute BWO if you do see surface activity

Tactics & Rigging

Set up a double-nymph rig with a Prince Nymph or Black Stonefly Nymph on point and a Zebra Midge or Pheasant Tail 14–16" above it on a tag off the tippet knot. Use 4X fluorocarbon to the anchor and 5X to the dropper. Add enough split shot to tick the bottom — in 173 CFS with a steep gradient, you'll need more weight than you think to get down in the faster pockets. Focus on the seam water just off the main current and the deeper slots behind mid-channel boulders, where fish will be holding out of the heavier flow.

If you catch a break in the snow and skies flatten to a solid overcast, drop the nymph rig and tie on a Parachute BWO with an RS2 emerger trailing 14" behind it on 6X fluorocarbon. Work the slower tailouts and the inside edges of bends — that's where rising fish will set up if the hatch comes off. Don't linger on the surface game if nothing materializes within 20 minutes; get back to nymphing the structure.

Access & Logistics

Snow showers today and tomorrow mean the road to the Big South Trailhead could be slick — check road conditions before heading up, especially above Rustic. Dress in layers and bring waterproof wading gear; wet wading is not an option in these temps. Crowds will be minimal given the weather, which is one of the few upsides of fishing a snow day on the upper canyon.

Stop by Jax Outdoor Gear or The Fly Shop of the Rockies in Fort Collins for flies, local intel, and to support the shops that keep this fishery on the radar.

Looking Ahead

Snow continues through Tuesday night before a partial clearing Wednesday — that mid-week window around 50°F could bring the first real BWO action of the week, so keep an eye on the forecast. With a light snow year in the basin, flows should stay fishable through May rather than blowing out hard, which sets up a longer-than-usual spring window on this section.

Verify current regulations with CPW before fishing — some stretches of this section are catch-and-release, artificial flies and lures only. The Cache la Poudre is Colorado's only federally designated Wild and Scenic River; tread lightly and leave the water better than you found it.