Snake River
The lower reaches from South Park Bridge down to Sheep Gulch is the place to be with fish concentrated in ledge rock pools, troughs with mid-range depth, backwater side channels, and seams. Whitefish egg patterns are working best in riffles and troughs (particularly those squeezed between riffle shelves and banks). Midge imitations are working in all water mention above). It has been a fairly wide window of activity, with consistent action happening from around 10:30am until around 3pm or 4pm.
Small streamers continue to work well in slow current side channels and ledge rock pools. The tail of troughs are also offering some action when swung within three or four feet of banks. Use floating lines or INT tips and slow retrieves. Give your streamers a countdown in deeper water (several seconds). Doubling you patters up – with a separation of three to five feet – is definitely worth considering when fish are actively feeding but not moving to a streamer fished slow.
Dry flies – Booty’s DL Cripple, Film Critics, Furimsky’s BDEs, Morgan’s Para Midge, Parachute Midges, CDC Wing Midge Emergers, and Chez’s Krystal Wing Midge Emerger.
Nymphs – Lightening Bugs, Copper Johns in red and black, Psycho Princes, Perdigons, Zebra Midges, Booty’s Day-2 Midge Pupa, Rojo Midges, Miracle Midges, Veiled Eggs, Otter’s Soft Milking Eggs, and Yarn Eggs.
Streamers – Arum’s Lil’ Kim, Booty Call Minnows, Kreelux, Slump Busters, Pine Squirrel Zonkers, and Rickards’ Seal Bugger.
South Fork
Slow currents are the place to be, and the South Fork a lot of it at the moment. Riffle pools are most productive target at the moment with seams and eddy current margins a close second. Flats also have some action in the afternoon, as do side channels (both are offering slow sipping trout for a couple hours from around 1:30pm until around 4pm on the lower reaches from around Wolf Eddy down to Lorenzo). Midges are emerging with a fair amount of gusto and all of these water types are worth fishing with either adult or larva/pupa patterns. Whitefish roe imitations are working best in riffle pools and seams.
Moderately sized streamers are working with more consistency over the past week and a half on the upper reach from the Dam down to Conant. Fish these on floating lines or sinking tips in the INT to 3ips range with slow to moderate retrieves and long line strips. Target side channels, seams, and riffle current margins (in that order).
Dry flies – Parachute Adams, Griffith Gnats, Renegades, Parachute Midges, Mating Midges, and CDC Midge Emergers.
Nymphs – Rainbow Warriors, Bruised Mays, Dorsey’s Mercury Baetis, Perdigons, Booty’s Day-2 Midge Pupa, Zebra Midges, Ice Cream Cone Midges, Cole’s Light Brite Serendipity, Otter’s Soft Milking Eggs, Clown Eggs, and Eyed Yarn Eggs.
Streamers – Mini Dungeons, Marabou Muddlers, Beldar Buggers, Krystal Buggers, Sculpzillas, Arum’s Lil’ Kim, J.J. Specials, and Kreelux.