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LOCAL WATER. LOCAL KNOWLEDGE.

Blue River Fishing Report

Silverthorne · Below Dillon & Green Mountain Reservoirs, Colorado

Plan your day on the Blue River with fishing conditions, reservoir-release flows, suggested flies, and practical advice from Blue Quill Angler.

ON THE WATER

Current fishing report

Report updated

The Blue below Dillon is holding a technical fall tailwater pattern. An October 18 reading near 67 cfs indicates modest, manageable flow in the Silverthorne reach, although dam releases can change. Cold water and good visibility favor midges, tiny Baetis nymphs and, near the dam, mysis imitations. Trout may hold in deceptively soft seams, deeper slots and the edges of current breaks rather than in the fastest water. Start with a carefully weighted nymph rig and adjust depth before changing patterns. On overcast afternoons, watch for subtle rises to BWO emergers and small dries. The Blue downstream of Green Mountain is a different fishery and should not be judged by the Silverthorne gauge. Protect spawning brown trout by avoiding redds and paired fish.

Fishing tips

Below Dillon, begin with a Zebra Midge and Juju Baetis or RS2 on light tippet; try a mysis imitation near the dam where appropriate. Carry a Blue Wing Olive dry for cloudy hatch windows. Check the release for the specific reach and avoid crossing shallow spawning gravel.
Pat Dorsey

FROM OUR HEAD GUIDE

Pat Dorsey's Guide Report

Pat's report revised

Tips & Other Information

Outflows below Dillon Reservoir are at 64 cfs.  Dillon Reservoir is at 62% capacity as of this morning. Fishing is technical with the low water so you’ll need to bring your A-game. Plan on reliable hatches of midges in the morning followed by some blue-wingeed olives in the afternoon. The feeders creeks are adding some water but not much to speak of. At least we got a little rain and snow over there last week…every little bit helps. .

14-Day Hatch Outlook

Outlook from Pat's report dated October 19, 2026; not a live weather forecast.

Look for hatches of midges, Tricos, and blue-winged olives.

Effective Patterns

#20-22 Top Secret Midge, #20-22 Manhattan Midge, #20-22 Jujubaetis, #20-22 Top Secret Baetis, #20-24 Chocolate Foam Wing Emerger, #18 Micro San Juan Worm, #20-22 Red Larva, #20 Mercurry Blood Midge, #20 Flashback Mercury Black Beauty, #18 Buckskin, #10 Amy's Ant, #16 PMD, #14-16 Elk Hair Caddis, #20 Mathew's Sparkle Dun, #22 Mole Fly, and #16-20 Parachute Adams.

Looking for flies for this river? Shop BQA's recommended flies ↓

Source: Pat Dorsey Fly Fishing · Read Pat's original report

KNOW BEFORE YOU GO

River conditions

Flow readings update separately from the fishing report. Check the reading time shown below.

BUILD YOUR FLY BOX

Recommended flies for Blue River

Selected by the Blue Quill Angler team for fishing Blue River. See the fishing reports above for specific patterns, sizes, and techniques.

PLAN YOUR DAY

Fishing Blue River

The fishery

The Blue River offers distinct fishing experiences below Dillon Reservoir, through the valley toward Green Mountain Reservoir, and below Green Mountain Dam. In Silverthorne, clear tailwater runs and defined feeding lanes reward patient observation and precise presentations. Other reaches differ in access, current, and available habitat. Select your destination before interpreting a flow reading, and avoid assuming conditions below one reservoir describe the entire river.

Access & parking

Silverthorne provides public fishing access at designated locations along the Blue River corridor, including River’s Edge Park. Use established parking and trails, and respect adjoining private property. Outside town, verify public boundaries before approaching the river. Access below Green Mountain Reservoir requires separate planning; check current road conditions, restrictions, and legal entry points rather than assuming the dam road or surrounding banks are open.

Seasons & techniques

Midges are important in the cold tailwater below Dillon, while small mayflies provide seasonal opportunities for nymphs, emergers, and dries. Mysis patterns can be useful where the food supply and feeding behavior support them. Warmer periods broaden the insect activity in other reaches. Reservoir operations can change flows independently of local weather, so check the appropriate gauge before fishing. Adjust depth and presentation to the water in front of you.

Regulations & river care

Check current fishing regulations for the exact reach you plan to visit; restrictions and property boundaries vary along the Blue River. We encourage catch and release, minimal handling, and keeping fish in the water while unhooking them. Avoid spawning trout and redds, give other anglers room, and use established paths. Treat changing releases, deep slots, and slippery rocks cautiously. A familiar crossing may become unsafe when flows increase.

PLAN YOUR VISIT

Location & access

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Willow Grove Open Space provides access to the Blue River Trail in Silverthorne. This location is for the town section, not the fishery below Green Mountain Reservoir. Use designated parking and respect posted boundaries.

Use the marked location to plan your visit. Follow current signs, access boundaries, parking rules, and closures on arrival.