Fly Fishing Stream Conditions Report: Blue River - Below Green Mountain Reservoir

This year: Current flows below the reservoir are averaging around 155 CFS, with daily rates fluctuating between 125 and 184 CFS, though some stretches have been observed lower, in the 55 to 70 CFS range. Higher flows are carrying a slight green stain, while the lower flows remain clear. Be highly cautious of spawning brown trout and avoid wading on or fishing near their redds. In the stained, higher flows, nymphing with small dark patterns or swinging small to medium black or white streamers is highly effective. On the lower-flow stretches, small dry flies can be very productive in the shallow water, but you will want a nymph rig to target larger fish holding in the deeper runs. Additionally, keep an eye out for Kokanee salmon near the reservoir, which can be triggered using red, pink, and orange colors. BWO, stonefly, and midge hatches are the primary focus. Great fly choices to keep in your box include the Two Bit Hooker, RS2, PGH Golden Stone, Parachute Adams, and the Slump Buster.

Best time of day: Afternoon

Prior years: October brings elevated flows of around 700 CFS below Green Mountain Reservoir, making the fishing a true challenge. Water temperatures hover around 51 degrees, requiring anglers to bundle up against cool fall weather and prepare for a nasty crosswind that can easily push casts back toward the shoreline bushes and branches. With high water running through the long slides and troughs, dry/dropper rigs may struggle, and anglers should consider switching to a deep nymphing setup with a strike indicator to reach the fish in shelf pools, moderate depth riffles, and deep slots around structure. While fish can be found rising to tiny mayflies, midges, and caddis, productivity is generally slow. Useful patterns to cycle through include amber ice dub Chubby Chernobyls, olive perdigons, RS2s, UV Sally nymphs, and deer hair caddis. Streamers like a black ghost or white and tinsel patterns can also be tested in these elevated flows.