The "tailwater" section of Blue River through Silverthorne fishes fairly consistently year round. Water temps normally stay within the lower forties (fahrenheit), which doesn’t produce a large variety of hatches. For the most part, small midge larva, and Mysis Shrimp (small white shrimp inhabiting Dillon Reservoir), are staples of the trouts diet. Things start to get more interesting if Dillon Reservoir reaches capacity and “spills” through the top release of the dam, instead of the bottom. This causes a larger variety of aquatic insects that live in the Blue River to become active, and therefore more available to trout.
The best technique is usually nymphing under a small, inconspicuous indicator. Adjust your weight and indicator depth depending on the depth of the piece of water you are working, and to the depth at which the fish are holding. Seeing rising fish is a possibility, as is seeing some action on streamers.
Nymphs To Try: size 18-22 Mysis Shrimp, size 18-22 Pheasant Tails in natural or black, size 20-22 Pure Midges in black, size 20-22 UV Midge in black, Big Bear Baetis 18-22, RS2 olive size 20-22, Chocolate Foam Wing size 22-24, red disco midge size 22-24, Juan's Flux Capacitor red size 20-22
Dries To Try: Matthew's Sparkle Dun olive size 22, Parachute Adams size 16-24, Extended Body Blue Wing Olive size 18-22, size 20-22 CDC Morgan's Midge
Streamers To Try: Sex Dungeons, Barely Legals, Home Invaders, Houdini, Thin Mints, Super Buggers and all sizes and colors of the standard "Woolly Bugger."
Winter has set in quickly here in Summit County, with cold temps and over 90 inches of snow in November! However that has not stopped the trout from feeding, or the insects from hatching for that matter. We are still seeing small Blue Wing Olives coming off mid-day and the fish are feeding on them. Small midges in brown, black, or red have also been working, as well as Mysis Shrimp here and there. Targeting actively feeding fish with a light weight double nymph rig, or double dry flies have been our go to technique. Some days the water has had a bit of stain from fresh snow melt, consider using a pegged egg as an attractor during these times (especially since the Blue was stocked in town a few weeks ago).
The Blue River in town is fishing consistently as usual, size 18-22 mayfly nymphs, 20-24 midge larva and emergers, and 18-22 Mysis Shrimp all fished underneath a small strike indicator, are the best bet at the moment. We have also been seeing a few more fish than normal rising, especially in the lower stretches through town, if you are dedicated to the dry fly all day you will probably get a few eats. The adult insects that we have been seeing on the water or in the air include, Sulphur Duns, Blue Wing Olives, a few sparse Tricos, and midges.
The Blue River below Dillon Reservoir has settled down into its “average” summertime flow and is running about 100 CFS. Fishing has been consistent with standard tailwater nymphing techniques using small midge larva, natural mayfly nymphs, and mysis shrimp. We have also been seeing decent dry fly action as small Caddis, and PMD’s have been hatching sporadically throughout town. Try fishing a size 18-20 black bodied caddis, or size 20 PMD pattern as a single dry fly, or followed by your favorite dry midge imitation.
The release from Dillon Reservoir is seeing a slow decline in stages, and is currently sitting at about 300 CFS. Mysis Shrimp are still high on the menu at these flows, especially in the early mornings and late evenings. Small realistic imitations of dark colored midge larva, and mayfly nymphs will be a good option to fish during the mid day hours. With lower flows the dry fly action can be better, especially when fish are sighted tight to the bank, or under overhanging foliage. Consider using small terrestrial imitations, midges, and tiny mayfly patterns.
The Blue River below Dillon Reservoir is now seeing higher spring run off flows, due to about 900 CFS of water being released from the bottom of Dillon Dam. Fishing can be tricky at these flows, but you can use thicker tippet (3x, 4x), and some larger nymphs as well. Any slower pockets of water that you see of decent size should be holding several trout. You can also find smaller pockets of slow water just big enough for one or two fish to hide in. Golden Stones, Craneflies, and Mysis Shrimp can be good options to consider fishing at this time. Small to medium streamers can also be effective at these flows.
The Blue River has been recently stocked in Silverthorne, fishing should be a bit easier than normal until the freshly minted trout become educated. Resident fish will still be picky and spooky, however. Flows are currently "average" for the Blue at about 100 CFS, but we should see higher releases soon as more high elevation snow melts.
Question: What's going on with the Gold Medal status of the Blue River?
Answer: The Blue River between Silverthorne and Green Mountain Reservoir has been delisted from Colorado's Gold Medal list. The Blue within the city limits of Silverthorne is still listed as Gold Medal water. There are still great fish to be caught from Silverthorne all the way to Green Mountain Reservoir (and below). If you check in with us regularly, you have seen hundreds of photos of fish that were caught in this stretch over the years, and many that were caught (and released) this year. It's true; you won't find the numbers of fish north of Silverthorne that you will see in Silverthorne. But you will find fewer anglers and less selective fish!