Big Thompson — Moraine Park (RMNP)

Big Thompson — Moraine Park (RMNP) — Fishing Report for April 27, 2026

Quick Stats

Flow: 25 CFS | Trend: Falling (-6% in 24h) | Fishability: Poor | Weather: Chance snow showers, high 49°F

The Bite

A multi-day snow event is bearing down on the park — Tuesday and Wednesday bring high-probability snow showers, and overnight lows are dropping into the upper 20s. Today is your last reasonable window before conditions tighten up, and even today you're working against a 38°F water temperature and a meadow that's still partially waterlogged from the spring thaw cycle. Manage expectations accordingly: this is a tough day to find active fish, but not an impossible one.

With water temps sitting at the low end of the active range, brown trout will be holding tight to the bottom of the deepest bends and tucked under the cut banks — conserving energy rather than chasing food. The fish are there; they're just not in a generous mood. A brief midge window is possible if afternoon temps push toward that 49°F ceiling and cloud cover thins out, but with snow showers in the forecast, don't count on a sustained surface bite. Think of any rising fish today as a bonus, not the plan.

It's also worth noting that this is a very dry water year across the South Platte basin — snowpack is well below normal, sitting around 16% of median. That means the typical late-April runoff pulse is likely to be mild and short-lived, which could actually open up fishable windows earlier than usual as we move into May. Today's falling flows support that picture. For now, though, the cold and the incoming storm are the dominant story.

What to Fish

• Zebra Midge #22-24 — Point fly, fished deep. The workhorse for cold, slow days like this.
• RS2 #22 — Trailing dropper 12–16" above the Zebra Midge; imitates emerging midges and early Baetis nymphs.
• Pheasant Tail #16-18 — Substitute for the point fly in deeper, slower pools where a slightly larger profile may draw a reaction.
• Parachute Adams #18-20 — Keep one rigged as a single dry if you spot a rise during any afternoon midge activity.
• Prince Nymph #16-18 — A searching option in the deeper bends if fish seem unresponsive to smaller patterns.

Tactics & Rigging

Rig a double-nymph setup with a Pheasant Tail or Zebra Midge as your weighted point fly, and trail an RS2 12–16" above it on a 5–6" tag off the main tippet. Use 5X fluorocarbon to the point fly — the cold, clear water calls for a light touch. Add enough split shot to get the rig to the bottom quickly; in 38°F water, fish aren't going to move far to eat. Focus your casts on the outside bends where the current has carved depth, and let the rig ride the bottom with as little drag as possible. Slow, deliberate presentations in short drifts will outperform covering water aggressively.

If you catch a midge hatch between noon and 3 PM, switch to a single Parachute Adams or a CDC midge emerger in #22 on 6X tippet and work any rising fish with a drag-free drift from downstream. Keep your profile low — the open meadow means fish can see you from a distance.

Access & Logistics

The Moraine Park meadow is accessible via the Bear Lake Road corridor inside RMNP — a park entrance pass is required. The meadow itself may be soft and wet in spots; waterproof wading boots or rubber-soled waders are worth the extra weight. With snow arriving Tuesday, trail and road conditions could change quickly — check NPS road status before heading up. Crowds will be light given the weather, which is one genuine upside to fishing this week.

Verify current regulations with CPW and NPS before fishing — RMNP has its own overlay rules and they can change. Stop by Estes Angler or Kirk's Fly Shop in Estes Park for flies, local intel, and to support the shops that keep these fisheries healthy.

Looking Ahead

Tuesday through Wednesday brings the heaviest snow of the week, which will likely push water temps down further and keep fish in a holding pattern through mid-week. If Wednesday's clearing trend holds and temps recover into the low 50s by the weekend, a brief midge and early BWO window could make for a more productive visit — keep an eye on the forecast.