Blue River: Silverthorne (Below Dillon Reservoir)

Blue River: Silverthorne — Fishing Report for April 24, 2026

Quick Stats

Flow: 56 CFS | Trend: Unknown | Fishability: Good | Weather: Sunny, High 56°F

The Bite

April on the Blue is the month dry fly anglers circle on the calendar, and this week is delivering the goods — with one asterisk. Today's sunny skies are the one condition that can put a ceiling on what should otherwise be peak BWO fishing. Bright overhead light suppresses Baetis emergences and pushes the hatch window later and shorter, so don't expect the dense, fish-everywhere surface activity that a gray, drizzly afternoon would produce. That said, midges are still likely to generate surface feeding from late morning through early afternoon, and a smattering of BWOs may come off in the 2–4 PM window as shadows lengthen. The fish are here and they're eating — the water is clear, cold, and stable at 41°F, and at 56 CFS the river is running lean and approachable.

The real opportunity this week arrives Saturday, when a chance of snow showers is in the forecast. Overcast skies and cold, damp air are the Blue's secret ingredient in April — those are the conditions that trigger heavy Baetis emergences and get even the river's most educated brown trout looking up. If you can be on the water Saturday afternoon, prioritize that over today. For today, plan on subsurface fishing through midday and stay alert for surface activity between 1 and 4 PM.

One note on the basin: snowpack in the Colorado headwaters is sitting at just 19% of normal this year — a historically dry water year. That means dam managers at Dillon are likely holding releases conservative, which explains flows running slightly below the 10-day average. Expect stable, low, clear conditions to persist rather than the modest April bump the seasonal outlook anticipated. Clear water at low flows means leader-shy fish — presentation is everything.

What to Fish

• Zebra Midge #22-24 — Point fly in a double-nymph rig; fish it slow and deep through runs and pools during the morning
• RS2 (gray) #22 — Dropper 12–16" above the Zebra Midge; deadly in the pre-hatch window and during sparse BWO activity
• Sparkle Dun BWO #20-22 — Switch to this when you see noses; natural drag-free drift on 6X or 7X through the feeding lane
• Griffith's Gnat #22-24 — Excellent midge cluster imitation for surface-feeding fish between 11 AM and 1 PM
• Mysis Shrimp #16-18 — For the biggest fish holding in deeper, slower water; fish it on a long, light leader near the bottom
• San Juan Worm (red) #14 — A reliable anchor pattern for a nymph rig when fish are ignoring smaller offerings

Tactics & Rigging

For the morning, rig a double-nymph setup with a San Juan Worm or Mysis Shrimp as your anchor on the point, and trail an RS2 or Zebra Midge 14–18" above it on 5X to 6X fluorocarbon. Use enough split shot to tick the bottom through the deeper runs and pools — the Blue's fish hold tight to structure in low, clear water. Keep your presentations long and your mends clean; at 56 CFS the current is gentle but the fish have all day to inspect your fly.

When surface activity picks up — watch for subtle sipping rises, not splashy takes — drop to a single Sparkle Dun BWO or Griffith's Gnat on 6X or 7X fluorocarbon and focus on individual rising fish. On this water, casting to a specific fish is almost always more productive than covering water. Get upstream of the rise, let the fly ride the seam untouched, and be patient. These fish have seen everything.

Access & Logistics

Access is straightforward through Silverthorne with multiple pull-offs along the river corridor. Crowds are typical for a Friday in peak season — expect company at the popular runs, especially in the afternoon. Arrive early or hike past the first few access points to find less-pressured water. Verify current regulations with CPW before fishing — this is Gold Medal, artificial-only water with catch-and-release restrictions on portions of the river, and boundaries matter.

Stop by Cutthroat Anglers in Silverthorne for flies, local intel, and to support the shops that keep this fishery healthy.

Looking Ahead

Saturday's snow showers could be the best fishing day of the week — overcast skies and cool temps are exactly what triggers heavy BWO emergences on the Blue, so if you can only pick one day, make it Saturday afternoon. Sunday brings rain, snow, and possible thunderstorms, which may push flows slightly but shouldn't push the river out of shape given how conservatively Dillon is releasing this dry year.