Blue River
Below Green Mountain Reservoir
N Colorado, USA
Open live forecast →Target species: Rainbow and Brown.
Stream gauge: 09057500. Flow and water temperature update on every refresh.
Weekly AI Outlook as of 07/31/26
The Blue below Green Mountain is running 337 cfs — on the higher end for late July, which means wading is technical and trout are stacked in softer seams along the edges rather than spread across mid-channel. With highs pushing into the mid-to-upper 80s and touching 90°F by Sunday, afternoon water temps are a real concern; fish hard in the first two hours of light and again as shadows hit the water in early evening. Expect Trico spinners in morning flat-water pockets once you find fish holding in the 60°F-plus zones — this river is well past that threshold in summer. Terrestrials are the other reliable tool right now: ants, beetles, and hoppers fished tight to the grassy banks should draw strikes through midday when aquatic activity slows. No recent shop intel — outlook based on current conditions and seasonal norms.
- Flow: 337 cfs — above typical late-July levels. Wade carefully; fish are pushed into edgelines and soft pockets off the main current.
- Hatches: Trico spinners on slower flats in early morning. Terrestrials (ants, beetles, foam hoppers) carry the afternoon once aquatic activity fades.
- Water Temp: Expect mid-to-upper 60s°F by afternoon with 84–90°F air temps forecast. Stress likely after 2pm — move to shaded runs or call it early.
- Best Window: 7–10am for Trico activity and cooler water. Secondary window: 6–7:30pm in shaded canyon sections as air temps drop and trout resume surface feeding.
Generated weekly from live USGS gauge readings, weather forecasts, and recent fly shop reports. Updates Friday mornings.
About this Water
- Tailwater
- Best months: Year-round; peak Apr–May & Oct–Nov
The Blue River below Dillon Reservoir is a compact Gold Medal tailwater in the heart of Summit County ski country. Massive rainbows and browns — with 20-inch fish common — feed in the cold clear currents flowing through a cottonwood valley toward the Colorado River. The accessibility and consistent fishing make it a top destination for Front Range anglers.
Despite running through a ski resort town, the Blue River's dam-regulated flows produce remarkably consistent fishing even during peak summer tourist season.
February Outlook
The Blue River below Dillon Reservoir is an excellent winter tailwater fishery. Midges year-round in one of Colorado's most consistent rivers.
Productive Patterns
- Zebra Midge
- RS2
- Juju Baetis
- Top Secret Midge
Tips
The section from Dillon Reservoir dam to Silverthorne fishes year-round. Winter fishing is consistent in the slow, clear pools. Approach carefully — fish are very wary.
Water Notes
Regulated 50–200 cfs. Water 42–50°F year-round. The dam creates ideal tailwater conditions even at high altitude.
May Outlook
Spring PMD and BWO activity on the Blue River tailwater. Less pressure than the Frying Pan or South Platte.
Productive Patterns
- PMD Sparkle Dun
- RS2
- Elk Hair Caddis
- Soft Hackle
Tips
The Blue River is often overlooked in favor of other Colorado tailwaters. Excellent fishing with less competition for water. The Silverthorne section is most accessible.
Water Notes
100–300 cfs. Water 46–54°F. Good spring conditions below Dillon Reservoir.
June Outlook
PMDs and Caddis produce consistent action on the Blue. A reliable June option when other rivers are in runoff.
Productive Patterns
- PMD
- Elk Hair Caddis
- Stimulator
- Soft Hackle Caddis
Tips
The Blue River tailwater insulates this fishery from Tenmile Creek runoff effects. Fish the upper section near Dillon for the most consistent action.
Water Notes
150–400 cfs. Water 50–58°F. Good June tailwater conditions.
September Outlook
Fall BWO season on the Blue River tailwater. One of Colorado's reliable late-season options.
Productive Patterns
- Blue Winged Olive
- RS2
- Mahogany Dun
- Streamer
Tips
The fall BWO hatch is reliable on the Blue River on overcast afternoons. Brown trout spawning activity in October makes them aggressive in September.
Water Notes
80–250 cfs. Water 46–54°F. Good fall tailwater conditions.
Hatch Calendar
| Insect | Peak | Active | Size | Productive Patterns |
|---|---|---|---|---|
| Midge Chironomidae |
Jan, Feb, Dec | Jan, Feb, Mar, Apr, Oct, Nov, Dec | #22–26 |
|
| Blue Winged Olive Baetis spp. |
May, Sep | Apr, May, Sep, Oct | #18–22 |
|
Access & Approach
Silverthorne, CO. Free public access along Hwy 9 corridor from dam to Kremmling. Walk-wade throughout. Several quality fly shops in Dillon and Silverthorne.
Nearby Fly Shops
- Mountain Angler
- Taylor Creek Fly Shop
- Vail Valley Anglers
- Minturn Anglers
- Cutthroat Anglers
- Colorado Angling Company
Regulations & License
Fishing in Colorado requires a current license. Always verify season dates, bag limits, and any special-regulation waters before you fish.
Colorado fishing regulations & license →
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About Current
Blue River conditions on Current combine real-time flow data (USGS, WSC, CDEC, CEHQ), weather, tide predictions, hatch probabilities calibrated to this specific water, and recent fly shop reports from the area.
Blue River is one of 245 hand-curated waters in Current. The app and web forecast also generate AI outlooks for any unlisted river, lake, or saltwater flat anywhere in the world — drop a pin or paste a name and Current produces a fresh seasonal outlook with weather, flow context, and recommended techniques.
Open the live forecast for today's numbers and the 7-day outlook, or download the iOS app to carry it with you on the water.