Blue River

Overview

The Blue River below Dillon Dam is one of Colorado's premier Gold Medal fisheries and arguably the best tailwater in Summit County. The river flows from the base of Dillon Reservoir through the town of Silverthorne and downstream toward Green Mountain Reservoir, providing approximately 4 miles of exceptional public water. The Gold Medal designation means the river sustains at least 60 pounds of standing trout biomass per acre, placing it among the most productive trout streams in the state.

Cold, nutrient-rich releases from Dillon Reservoir create ideal conditions for both brown and rainbow trout, with fish averaging 14 to 18 inches and plenty of larger specimens throughout the system. The river's character shifts between deep, slow pools near the dam and faster pocket water downstream, offering varied fishing opportunities. The Blue River is a technical fishery that rewards patience, fine tippets, and precise nymphing techniques.

Fishing the Blue River requires adapting to its flow regime. Denver Water controls releases from Dillon Dam to meet downstream water commitments, which means flows can fluctuate significantly. During winter and early spring, flows typically run 50 to 100 CFS, providing ideal wade fishing. Summer releases can push flows above 300 CFS, making wading difficult or impossible in some sections. Understanding the release schedule is key to planning a successful trip.

Access & Parking

The Blue River below Dillon Dam is easily accessed from Interstate 70 at Silverthorne (Exit 205). The drive from Denver takes approximately 1 hour 30 minutes. The river runs through and alongside town, making access exceptionally convenient.

• Below the Dam: The most productive stretch begins directly below Dillon Dam at the outlet works. Park at the Blue River trailhead parking area near the dam. This section has the deepest pools and coldest water, and often holds the largest fish.
• Silverthorne Town Section: The river flows through Silverthorne with numerous access points along the Blue River Trail, a paved path that parallels the river. Parking is available at several trailhead lots and town parking areas. This is the most accessible section for walk-and-wade fishing.
• Below Silverthorne: Downstream of town, the Blue River enters a more rural setting. Access points become less frequent, but fishing pressure drops substantially. The river eventually reaches Green Mountain Reservoir.

Regulations

• Tackle: Flies and lures only in the Gold Medal section below Dillon Dam.
• Bag limit: Catch and release only.
• Gold Medal designation: The Blue River is classified as Gold Medal by Colorado Parks and Wildlife.
• Season: Open year-round.
• License: A valid Colorado fishing license is required.

Seasonal Guide

Recommended Flies

Tips from Locals

• Check flows before driving. The Blue River's fishability depends almost entirely on dam releases. Check the USGS gauge online before making the drive. Below 150 CFS is ideal for wading. Above 250 CFS, consider fishing another river unless you are targeting the dam outlet pool.
• Think small. Blue River trout are heavily pressured and highly selective. Standard advice applies: go smaller and lighter than you think. Start with #22-24 midges on 6X or 7X fluorocarbon tippet.
• Depth is everything. In the deeper pools near the dam, your flies need to be right on the bottom. Use enough split shot to tick the bottom and adjust your indicator depth frequently as pool depth changes. Euro-nymphing (tight-line) techniques are highly effective.
• Walk past the obvious spots. The first few pools below the dam get hammered. Walk downstream 15 to 20 minutes and fish the less-obvious runs and pocket water. The trout density is high throughout the Gold Medal section.
• Winter is prime time. Many anglers avoid the Blue River in winter, but low flows and consistent midge hatches make December through February some of the best fishing of the year. Layer up and fish midday.
• Respect private water signs. Some stretches along the Blue River downstream of Silverthorne cross private property. Stay within marked public access areas and respect posted boundaries.