Blue River below Green Mountain Reservoir Fishing Guides and Conditions, Colorado

About the Blue River below Green Mountain Reservoir

The Blue River is a tailwater three times over, dropping out of Dillon Reservoir at Silverthorne, running down through Summit County, entering Green Mountain Reservoir, and then emerging below Green Mountain Dam for a short final run to the Colorado River at Kremmling. The USGS gauge below Green Mountain Reservoir reads that last reach, and it is the one most Colorado anglers mean when they talk about the lower Blue. The gauge reports discharge and stage without a current water temperature series, so release volume is the number that governs both fishing quality and safety here.

This reach fishes very differently from the more famous Silverthorne water above. Below Green Mountain the river runs through a steep, rocky, partly canyon-bound section with genuine gradient, big boulder pockets and deep slots, and it holds a population of brown trout that grow large on a rich food base and on the kokanee that drop out of the reservoir. Rainbow trout are present throughout, mountain whitefish are abundant and often overlooked, and cutthroat and brook trout come in from the tributaries. The autumn kokanee run out of Green Mountain is a well-known event and pulls both salmon anglers and the browns that follow them.

Access is the constraint that shapes the fishery. The reach below the dam runs through a mix of Bureau of Land Management and private ground, with the Blue River State Wildlife Area and BLM parcels providing the public water, and a good deal of ranch frontage between them that is genuinely closed. Most fishing is wade fishing; the canyon is not a float. Guides based in Silverthorne, Frisco and Kremmling run walk-and-wade trips here, often pairing the lower Blue with a float on the Colorado at Kremmling.

Everything turns on the release schedule. Green Mountain is a Colorado-Big Thompson storage unit and its releases swing hard, from a few hundred cubic feet per second in winter to well over a thousand during summer operations, and high release makes the canyon unwadeable rather than merely difficult. Late summer through October, when releases drop and the kokanee move, is the prime window. Colorado licenses are required and the regulations linked below carry current limits and any special provisions on this reach.

Access

Green Mountain Dam below-dam access at the USGS gauge - the release reference and the head of the fishable reach.
Blue River State Wildlife Area - the main block of public wade access below the dam.
BLM parcels along the lower canyon - walk-in access between private ranch frontage.
Highway 9 pullouts between Green Mountain and Kremmling - roadside access to the lower reach.
Kremmling and the Colorado River confluence - the downstream end and a common float take-out.
Green Mountain Reservoir ramps - trailer access to the impoundment above the tailwater.
Spring Creek and Cataract Creek confluence areas - tributary mouths and walk-in access points.

Seasons

Spring: high, cold and often unfishable during runoff and reservoir fill; the canyon is dangerous at peak release.
Summer: heavy irrigation releases keep the river big; wade with care and fish the edges and pockets.
Fall: releases drop in September and October, the kokanee run out of the reservoir, and the big browns feed hard.
Winter: low steady release and cold clear water, with technical but productive fishing for browns and whitefish.