Blue River
Insights
The Blue River runs about 65 miles from Hoosier Pass through Breckenridge and Dillon Reservoir, then below Dillon through Silverthorne, on through Green Mountain Reservoir, and out to its confluence with the Colorado River at Kremmling. Three distinct fly-fishing fisheries: the upper river above Dillon Reservoir through Breckenridge (small, technical, and not particularly highly regarded), the Silverthorne tailwater below Dillon Dam (an unusual urban C&R tailwater running through the Outlets Mall), and the lower Blue below Green Mountain Reservoir (the river's most respected stretch and a Gold Medal fishery from the dam to the Colorado confluence).
The Silverthorne tailwater fishes year-round on stable cold releases from Dillon. The 'Outlets Mall' stretch is the most-photographed urban fly-fishing water in Colorado — concrete walls, parking-lot access, and big selective rainbows feeding on Mysis shrimp flushed from Dillon Reservoir. Mysis dominates the diet immediately below the dam; tiny midges and BWOs fill in the rest of the year. The technical fishing rivals Cheesman Canyon for difficulty — selective fish, heavy pressure, and constant Mysis competition. Below the C&R section the river continues as a public-fishing stretch for about 6 miles to Green Mountain Reservoir.
Below Green Mountain Reservoir the Blue becomes a different fishery — bigger, freestone-like flows, wild brown trout, and 14 miles of Gold Medal water down to the Colorado at Kremmling. The lower Blue fishes hopper-dropper through August-September and produces the river's biggest fish in fall on streamers. Wade access is BLM-managed below Green Mountain Dam; drift boats are common on the lower reaches. The lower Blue has a seasonal closure from September 15 through December 1 to protect spawning brown trout. Drive times: 90 min from Denver to Silverthorne, 2 hr from Denver to Green Mountain Reservoir. Elevation 7,500 ft (Kremmling) to 9,000 ft (Silverthorne). Hwy 9 follows the entire river.
Species
| Species | Abundance | Best Season | Size | Notes |
|---|---|---|---|---|
| Rainbow Trout | Common | Year-round | 14-22" | Wild and stocked. Trophy rainbows in the Silverthorne tailwater feed on Mysis shrimp — fish to 24 inches are caught regularly. Wild populations also strong below Green Mountain Reservoir. |
| Brown Trout | Abundant | Sep-Nov | 12-22" | Dominant species on the lower Blue below Green Mountain Reservoir. Wild population with strong fall spawn — note the Sep 15-Dec 1 lower river closure to protect spawning fish. |
| Mountain Whitefish | Common | Year-round | 10-16" | Native and abundant on the lower Blue. Aggressive nymph eats year-round. |
| Cutthroat Trout | Limited | Jul-Sep | 8-14" | Native populations in upper headwater tributaries above Dillon. Not a target on the mainstem. |
Sections
Lower Blue — Spring Creek to Colorado River (Kremmling)
FloatBrown Trout · Rainbow Trout
Lower Blue — Green Mountain Dam to Spring Creek
Wade & FloatBrown Trout · Rainbow Trout
Silverthorne to Green Mountain Reservoir
WadeBrown Trout · Rainbow Trout
Silverthorne Tailwater — Dillon Dam to Hwy 9 Bridge
WadeRainbow Trout
Upper Blue — Breckenridge to Dillon Reservoir
WadeBrown Trout · Rainbow Trout
Regulations
Two distinct regulation zones. Silverthorne tailwater: catch-and-release artificial-only on the upper stretch. Lower Blue below Green Mountain Reservoir: Gold Medal water with C&R and seasonal closure to protect spawning brown trout (closed Sep 15-Dec 1, 2026 update).
Access & Logistics
Getting There
Silverthorne, CO (upper tailwater); Kremmling, CO (lower river / Green Mountain area)