Snake River
Decent fishing on the lower reaches from South Park Bridge down to Alpine as midges and BWOs emerge in strong numbers most days. Expect the action to start a little after 11am and build until 5pm (the sweet spot being from around 1pm to 4pm). Riffles and seams are fishing best early. Ledge rock pools, eddies, and slow currents along structure fish best later in the day. One caveat is that the head of riffles are also fishing well in the afternoon hours, and fish are actually holding and feeding on shallow riffle shelves. Nymphs are working in the same water as dries and are fished most effectively as part of a dry-dropper rig with short dropper leader – no longer than two and a half feet – when targeting slow currents or shallow depths.
Streamers are fishing in an inconsistent fashion but produce best on the lower reaches when targeting eddy pools, submerged structure, and tight troughs. Floating lines with slow to moderate retrieves is the name of the game. Short, 7ft lengths of INT or 3ips tips are also worth trying if you get the feeling that going deeper is more productive. Go small to moderate in size with your patterns.
Dry flies – Micro Mary Kays, Micro Bruces, Parachute Adams, Parachute Extended Body BWOs, Olive Comparaduns, Booty’s DL Cripple, Booty’s BWO Emerger, Film Critics, Parachute Midges, Ritt’s ARF Midge Adult, Mating Midges, and CDC Midge Emergers.
Nymphs – Duracells, Keller’s Peach Fuzz, Flashback Pheasant Tails, Military Mayflies, Juju Baetis, Zebra Midges, Ice Cream Cone Midges, Frenchies, and Perdigons.
Streamers – Arum’s Lil’ Kim, Baby Bunnies, Booty Call Minnows, Coffey’s Sparkle Minnow, Beldar Buggers, Slump Busters, Lite Brite Zonkers, and Kreelux.
South Fork
Fishing is best on the lower reaches from Wolverine down to Lorenzo. It is a typical midge and BWO fest with the best surface action coming in the afternoon hours from around 1 pm until 5 pm. Some left over October caddis are around, but don’t expect to see more than just a couple a day. Riffles are key targets, as are seams and eddies with slow currents. Action on the upper reaches is best on those days with cloud cover and some precipitation. Hit the same water as you would on the lower reaches.
Nymphs are fishing well on most reaches with small-ish mayfly and midge patterns working best. Soft hackle nymphs are a good second choice. Expect a fair amount of action on egg patterns, as whitefish get into prime time for spawning. Target riffles and flats (especially with egg patterns), seams, eddies, submerged structure, and parallel drop-offs.
Streamers are producing in a best when targeting the right water, primarily submerged structure, the head of riffles, and the full length of troughs. Smaller and moderately-sized patterns working best. Fish these on floating lines for the most part, but go heavy with your baitfish imitations, letting them be your wait.
Dry flies – Parachute Adams, Parachute Extended Body BWOs, Snowshoe Duns, Booty’s DL Cripple, Booty’s BWO Emerger, Parachute Midges, Ritt’s ARF Midge Adult, and CDC Midge Emergers.
Nymphs – Cyclops, Brillion’s Lucent Jig, Flashback Pheasant Tails, Military Mayflies, Redemption BWOs, Juju Baetis, Zebra Midges, Ice Cream Cone Midges, Spanish Bullets, and Perdigons.
Streamers – Arum’s Lil’ Kim, Booty Call Minnows, Flesh Fry, Doc’s Articulator, Baby Bunnies, and Slump Busters.