Blue River Fishing Forecast
Fly fishers plan Colorado trips on the Blue River because it stacks credible wading access, recognizable insect cycles, and trout that respond when flows align. Below-dam hydrology keeps dissolved oxygen high through summer—ideal for rainbow trout, brown trout, and cutthroat trout when roadside freestones climb past comfortable temperatures. River-specific intel: The Blue River offers technical tailwater fishing below Dillon Dam with some of Colorado's most educated trout. Trophy brown and rainbow trout thrive in the cold, clear water. USGS gauge 09050700 tracks live flow and temperature for planning wade or float days.
The Blue River tailwater is sitting at 54 CFS with a stable 43°F°F reading. Today's rating: 5/10. Top pick: a WD-40.
Season ends Sep 14
CLOSED Sep 15 - Dec 1 to protect spawning brown trout (below Dillon Reservoir). Below Green Mtn Dam is Gold Medal
Forecast and on-page guide updated September 9, 2026 (UTC). Open the app for hourly conditions.
Today's Fishing Conditions
Fair
Updated 8:24 AM
43°F
54 CFS
5 AM - 7 AM
WD-40
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What Makes the Blue River Unique?
Signature hatch or window
BWO (Mayfly) is a headline hatch to watch in September. Peak activity often tracks 40–50°F water temps.
Distinctive access
Green Mountain Reservoir: Below dam tailwater section.
Rules anglers miss
Gold Medal water with special regulations below Dillon.
Optimal Fishing Conditions
Optimal Flow
60 - 200 CFS
Best fishing conditions
Optimal Water Temperature
45° - 58°F
Ideal for active trout
Quick Facts
Rainbow Trout, Brown Trout, and Cutthroat Trout
tailwater
48°F - 56°F
September Hatches
BWO
Mayfly
Technical tailwater BWO. Year-round fishery. Overcast prime. 6X-7X tippet essential.
Mysis Shrimp
Crustacean
Primary food source year-round. Mysis patterns critical. Fish grow fat on shrimp.
Scud
Crustacean
Year-round scud fishing. Pink, gray, olive patterns.
September Fishing Tactics
Primary Targets
Recommended Tactics
Fall BWOs return. Excellent dry fly.
Year-Round Fishing Guide
| Month | Water Temp | Tactics |
|---|---|---|
| January | 38-45°F | Midges, BWOs, Scuds, Sowbugs |
| February | 38-46°F | Midges, BWOs, Scuds |
| March | 40-48°F | BWOs, Midges, Early PMDs |
| April | 42-50°F | BWOs, Midges, PMD nymphs |
| May | 45-52°F | BWOs, PMDs, Caddis |
| June | 48-55°F | PMDs, Caddis, Tricos starting |
| July | 50-58°F | PMDs, Tricos, Caddis |
| August | 50-60°F | Tricos, PMDs, Hoppers |
| September(Now) | 48-56°F | BWOs, Tricos, Streamers |
| October | 45-52°F | BWOs, Midges, Streamers |
| November | 42-48°F | BWOs, Midges, Scuds |
| December | 38-45°F | Midges, BWOs, Scuds, Sowbugs |
Recommended Equipment for Blue River
Rod
9-foot, 4 or 5-weight for technical fishing.
Line
Floating line with long leaders.
Leader & Tippet
12-15 foot leaders, 5X-7X tippet.
Waders
Breathable waders. Water is cold year-round.
Essential Flies
How to Fish Blue River: Tips & Tactics
The Blue River offers technical tailwater fishing below Dillon Dam with some of Colorado's most educated trout. Trophy brown and rainbow trout thrive in the cold, clear water.
Best Times of Day
Midge hatches occur year-round - mornings are best for surface activity. PMD and BWO hatches bring selective feeding. Evening can be productive during caddis activity.
Recommended Techniques
Technical presentations are required - use fine tippets and small flies. Match the midge and mayfly hatches precisely. Sight fishing to specific trout is often possible.
Water Conditions
Tailwater flows from Dillon Dam create stable, cold conditions. Water clarity is excellent. Fish are educated from heavy pressure.
Fly Selection
Midge patterns in sizes 18-24 are essential. Blue-winged olives and PMDs for mayfly hatches. San Juan Worms work year-round. Scuds in the lower sections.
When is the Best Time to Fish Blue River?
Spring
BWO hatches bring selective fish to the surface. Excellent nymphing.
Summer
PMD hatches and terrestrials. Fish early to avoid crowds.
Fall
Brown trout become aggressive. Streamer fishing can be excellent.
Winter
Year-round fishery with midge focus. Fish during warmest hours.
Access Points & Parking for Blue River
Green Mountain Reservoir
Below dam tailwater section.
Silverthorne
Town access to productive water.
Dillon Dam
Below Dillon Dam with technical fishing.
Blue River Campground
Lower river access with camping.
Spawning Seasons
Please respect spawning fish and their redds. Avoid fishing over actively spawning trout.
Brown Trout
Spawn months: October, November
Night spawning common. Males become very dark with pronounced kype during spawn.
Rainbow Trout
Spawn months: March, April
Resident rainbow trout spawn in smaller tributaries and tend to build smaller redds than steelhead.
Cutthroat Trout
Spawn months: May, June, July
Spring spawners. Timing varies by subspecies and elevation - coastal populations spawn earlier (Feb-Mar), inland populations later (May-July). Eggs develop for 6-7 weeks before hatching.
Blue River Fishing Regulations
Season
Open year-round.
Limits
Check current Colorado Parks and Wildlife regulations.
Special Regulations
Gold Medal water with special regulations below Dillon.
Bait Restrictions
Artificial flies and lures only in Gold Medal sections.
Notes
Technical fishing requires patience and skill.
Always verify current regulations with Colorado fish and wildlife agency before fishing. Regulations can change annually.
Fly Shops & Guides Near Blue River
Local Fly Shops
- Cutthroat Anglers - Silverthorne
- Blue Quill Angler - Evergreen
- Alpine Fly Fishing - Dillon
Guide Services
- Cutthroat Anglers Guides
- Blue River Guide Service
- Alpine Fly Fishing Guides
Other Rivers You Might Like
Popular forecasts outside Colorado—great for trip planning and comparing conditions.
Other Colorado Trout Rivers
South Platte (Cheesman)
Gunnison (below Taylor)
Animas
Fryingpan
Arkansas River
Blue River — frequently asked questions
When is the best time to fish the Blue River?
Fall BWOs return. Excellent dry fly.
What flies should I bring to the Blue River?
For the Blue River (tailwater), carry: Midge, RS2, BWO, PMD, San Juan Worm, Scud.
What water temperature is best for trout on the Blue River?
On the Blue River, trout hold between 45° and 58°F. Because the river is dam-fed, the temperature stays in this band year-round.
Do I need a fishing license for the Blue River?
Yes — you need a valid Colorado fishing license to fish the Blue River. Local season: Open year-round.. Daily limit: Check current Colorado Parks and Wildlife regulations..
What hatches should I watch for on the Blue River in September?
BWO is the signature hatch on the Blue River in September. Match size and adjust leader size to 5X-6X. The fish key in on the emergence during low-light hours, so plan to be on the water at first light.
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