Fly Fishing Blue River - Below Dillon Dam

Fly fishing Blue River below Dillon Dam unveils a striking turquoise corridor as cold, regulated releases from Dillon Reservoir carve a tailwater through dense lodgepole pine, aspen groves, and towering limestone cliffs. In this below-Dillon-Dam stretch out of Silverthorne, Colorado, flows hold steady between 100 and 300 CFS year-round—ideal habitat for trophy rainbow and wild brown trout. As you wade beneath US Highway 6 and alongside the Silverthorne outlet shops, the river’s crystal-clear, glacial-tinted water creates prime sight-fishing opportunities that reward both novice and expert anglers.

In early spring (March–May), the Blue below Dillon features prolific midges and blue-winged olive hatches in shallow riffles just downstream of the dam, bringing rising trout into pale green seams along cobblestone banks. Nymph anglers find success probing boulder-studded flats with midge larva and perdigon patterns, while tight-line dry-dropper rigs work under willow overhangs. By late spring and early summer (June–July), emerging mayfly and caddis populations light up in faster runs near the Silverthorne park access, and hopper action begins in sandy glides as temperatures climb. Terrestrial bugs such as beetles and ants drift onto the river during July and August afternoons, triggering explosive surface strikes in slack water near pocket currents.

Fall (September–October) transforms the canyon with golden aspens and cottonwood stands lining the banks, while stable flows reveal hidden gravel bars and deep tailouts where trout feed aggressively on emerging midge clusters. Tight-line nymphing under late-season mayfly activity produces consistent hook-ups, and swinging soft-hackle streamers through deeper pools can fool larger fish preparing for winter. Even in winter, when snow blankets the canyon rim, steady releases from Dillon Dam prevent icing, making nymph and streamer tactics effective under frozen banks and ice shelves.

Access is simple: park at the Silverthorne boat ramp or the river park downstream of Exit 205, then wade into riffles and deep holes that lie just steps from the highway. Check our live Blue River flow gauge and hatch chart to dial in water temperatures, flow rates, and insect activity before you head out. Whether you’re stalking rainbows in winter’s crystal currents or sipping dries under sunlit aspen leaves in summer, the Blue River below Dillon Dam delivers year-round trophy trout action amid unforgettable Rocky Mountain scenery.